%% Zero context examples and poorly written examples have been removed. If you want to re-add an example or add a new provide contexts that fully explains how the character fits the trope.
Significant characters on ''Series/TheBigBangTheory'', and their associated tropes.


!The Core Group
[[folder:Leonard Hofstadter]]
!!Leonard Leakey Hofstadter, Ph.D.
->'''Played by''': Johnny Galecki
--> ''Twelve years after high school and I'm still at the nerd table...''

Ostensibly the main character, Leonard is the most normal of the guys by having no outlandish quirks and generally operates as the OnlySaneMan. He (and his friends) work at Cal Tech, his field being in Experimental Physics. He has lived with Sheldon since late 2002 and is his best friend, though Sheldon's quirks annoy him to no end. He instantly gained a crush on Penny when she moved into the apartment across the hall and much of the show is about how they both change from interacting with each other.
* AbusiveParents: His mother is an iceberg of a woman who has never shown him any affection or approval. It's implied that this gave him emotional connection issues and he doesn't really know how to get close to anyone. He never celebrated a birthday until Penny threw him a surprise party, his own words were "we celebrated accomplishments in my family and being expelled from a birth canal wasn't one of them." In this case, he actually didn't seem to mind lacking that experience, although he was grateful for the gesture from his friends.
* {{Adorkable}}: This is even [[LampshadeHanging lampshaded]] in a Season 6 episode, when [[https://www.youtube.com/watch?v=GwiTBT-wfZQ Sheldon's new assistant reveals her crush on him]]. Penny feels very insecure and angry that Leonard didn't tell her personally, so Leonard comes to apologize by playing his cello in the melody of "Mary Had A Little Lamb."
-->'''Leonard:''' ''Sorry Alex hit on me, hit on me, hit on me,''\\
''Sorry Alex hit on me,''\\
''I had no idea I'm cute.'' *goofy grin*\\
'''Penny:''' ({{Beat}}) ''Damn it, you ''are'' cute''.
* AfraidOfNeedles: Leonard is so afraid of having to get stitches for his hand that he vomits -- and when Howard sees them, so does he.
%% * {{Angrish}}: Reduced to this at the end of "The Itchy Brain Simulation".
* BetterAsFriends: His relationship with Penny goes back and forth from this. Even though things are less complicated when they aren't together, there is no denying their attraction to each other.
* BigGuyLittleGuy: The Little Guy to Sheldon's Big Guy. Sheldon is 6' 1" (1.86 m) and towers over the 5' 5" (1.65 m) Leonard.
* BlindWithoutEm: When Leonard's glasses are accidentally broken at the movie theatre, his eyesight is so bad that he doesn't have any hope in watching the film, so has to return to his apartment (and risk running into a sick and needy Sheldon) just to get his spare pair.
* BrainyBrunette: A male version of this trope, he did go to Princeton and holds a Ph.D.
* BrilliantButLazy: According to Sheldon and his mother, since Leonard does very little original research of his own. Although his work in confirming the results of others' experiments ''is'' crucial work in validating modern scientific theories, but [[InsufferableGenius people like Sheldon and Mrs. Hofstadter]] are unlikely to appreciate this [[{{Irony}} even though they rely on scientists like him regularly.]]
* BrokenBird: The emotional abuse he suffered from his mother (being apathetic to his accomplishments and using him as examples in her psychology books) is the reason behind his insecurities and neediness. It's hinted at repeatedly through the show that part of Penny's attraction to him is recognizing he sometimes just needs a hug and the positive response from her affection. Leonard discovered that truth in the seventh season after questions about his mother's book for a psychology class brought on another depressed stage, with Penny being much more attentive to him afterwards ([[FawltyTowersPlot which he tried to exploit, which ended badly]]).
* ButtMonkey: The show has gone out of its way, particularly in later seasons, to make his life MORE AND MORE miserable...and it's always PlayedForLaughs, regardless of Leonard's progressively damaged psyche.
* CharacterDevelopment: He was always friendly and desired to be more social, but he had a hard time making friends and dealing with the opposite sex, the first season especially had him as painfully shy when in awkward situations. Interacting with Penny his already existent skills multiplied to where he is far less likely to put his foot in his mouth in the process. Penny even comments that she is the one who crafted him into becoming decent boyfriend material.
* CloudcuckoolandersMinder: To Sheldon, to the extent that Leonard sometimes appears in Sheldon's dreams to advise him on real life.
-->'''Leonard''': I'm not here, Sheldon. You're having a guilt-ridden dream. \\
'''Sheldon''': Oh, that's absurd.\\
'''Leonard''': Then why is that [[http://en.memory-alpha.org/wiki/Gorn gorn]] sitting there?
* CluelessChickMagnet: He is still stuck in a frame of mind where he is a nervous geek who has to work really hard to get a girl's attention, when the truth is he has actually become far more social and friendly, and that has made him be far more attractive to the opposite sex.
--> '''Alex''': You're cute, you're funny. Maybe you're getting hit on and you don't even know it.\\
'''Leonard''': Really?\\
'''Alex''' (stunned): I'm... pretty sure...\\
'''Leonard''': ({{Beat}}) Hahahahaha! I gotta get back to work, thanks for listening.\\
'''Alex''': (disappointed) No problem.\\
'''Leonard''': Hope -- hope no girls rip my clothes off on the way! Hahahaha!
* CoolLoser: Attractive and gregarious enough as a person, his previous problems with women were due more to his awkward personality.
* CrazyJealousGuy: Notably, the only time he starts doing the "crazy" part was in a sixth season episode regarding Penny working with a classmate, confronting the guy with an anonymous tip that her boyfriend has "gang" connections. Before this, he could certainly seethe with jealousy at times, but rarely did it manifest in something crazy. In the Thanksgiving episode, he ends up hounding Penny to divorce Zack[[note]]It was a Las Vegas wedding, which Penny believed was fake[[/note]]. Sheldon suggests that it frustrates him because Penny resolutely rejects Leonard's proposals but could easily get married to Zack
* DeadpanSnarker: Around Sheldon, at least. Sheldon, being LiteralMinded and often SarcasmBlind, doesn't always catch it, even occasionally interpreting Leonard's snarky responses as genuine.
* DoggedNiceGuy: He could provide a trope image, spending the first two seasons pining after Penny.
* EmbarrassingFirstName: He mentions that he doesn't like the name Leonard because it ends in the syllable "-nerd". Then again, he was off his tits on cannabis cookies at the time, so whether this was a spontaneous expression of a long-held resentment or a drug-induced epiphany that he forgot when he stopped rattling is up in the air. Although he is aware that his name is dorky when sober on some level
--> '''Penny:''' You play the cello? \\
'''Leonard:''' Yeah, my parents though that naming me Leonard and putting me in all AP classes wasn't getting me beat up enough.
* EmbarrassingMiddleName: Leonard '''Leakey''' Hofstadter. (It has nothing to do with his history of bed wetting.)
* EvenTheGuysWantHim: When Leonard demonstrates to Raj how he can be more popular with girls by being more confident ([[TheGlassesGottaGo and removing his glasses]]). [[StupidSexyFlanders Raj is mesmerized by it]].
* EverythingsBetterWithPrincesses: What does Leonard do when he sees Penny as Disney/SleepingBeauty aka "Princess Aurora"? He starts getting naked!
* FatalFlaw: Leonard's own insecurity about being considered a good match for Penny is one, which may be why it fuels his CrazyJealousGuy tendencies.
* FourTemperamentEnsemble: The Phlegmatic. He is the resident NiceGuy, the one his friends (particularly Sheldon and Penny) can depend on, incredibly patient, and tends to forgive slights on his person.
* FrickinLaserBeams: His specific field of study usually goes towards experiments involving lasers. He got a government grant to experiment on their weapons application but jokes on how far they are from practical use "I can remove hair from 2 miles away!"
* TheGlassesGottaGo: Played with. It's been noted that he has nice eyes/looks more handsome without his glasses, but he's BlindWithOutThem and his attempt at using contacts left him with an eye patch.
* HeightAngst: He is always complaining about how short he is, and is often mocked for it.
* HeterosexualLifePartners: While their relationship isn't quite as good as Howard and Raj's, ultimately Leonard and Sheldon are inseparable and both need the other despite the many times they irritate each other.
* HollywoodDateless: At times, though it has been made pretty clear that interacting with Penny has greatly improved his dating life (even outside of Penny herself).
* HollywoodNerd: Big time. Johnny Galecki may be short, but he's also gorgeous and ripped. However, a combination of makeup, wardrobe, and Galecki's performance actually manage to make his nerd status almost believable.
* InSeriesNickname: His aunt called him "Lenny". The nickname is used occassionally by Sheldon and Penny.
* LimitedWardrobe: Tends to wear a khaki jacket with a built in hoodie and "dorky" t-shirts like the recycle symbol or the chemical composition of caffeine, along with flat soled shoes and corduroy pants. But he does have two different ''Star Trek'' uniforms, dress and casual!
* LiterallyLovingThyNeighbor: With Penny. Sheldon's mother points this out almost word for word in an episode.
* LovableNerd: Leonard is adorably geeky, and easily the nicest and most likable of the four guys. It helps he's very often TheWoobie.
* LoveInterest: For Penny, thus providing much of the show's plot impetus.
%% * MasculineGirlFeminineBoy: Feminine Boy to Penny's Masculine Girl.
* MeaningfulName: Named for television producer Sheldon Leonard, anthropologist Louis Leakey, and the Hofstadters (Richard, [[Literature/GodelEscherBachAnEternalGoldenBraid Douglas]], etc.).
* {{Nerd}}: Even amoung the group, Leonard is not considered to be handsome. His inhaler and collection of allergies also cement his status as being socially awkward and undesirable.
* NiceGuy: Despite his tendency to snark at everything, Leonard's one of the nicest guys out of the main four.
* ObliviousToLove: See CluelessChickMagnet above, Sheldon's assistant, Alex, makes it blatantly obvious that she likes him by listing reasons why other women would like him. He just laughs it off. Later in the episode, he gets a blatantly-flirty text from her and just thinks aloud: "What a friendly girl..."
* OfficialCouple: With Penny, as it is pretty clear they are the main romantic relationship of the series.
* OnlySaneMan: Easily the most "normal" of the geeks. He even frequently acknowledges what he and his friends are doing is completely insane, although he usually participates anyway. He does have his moments of insanity though such as in "The Itchy Brain Stimulation" which ironically has Sheldon at his sanest.
* OvershadowedByAwesome: Unlike Sheldon, he comes from a family of well educated people who apparently are far more famous in their respective fields: an anthropologist father, a psychologist/neurobiologist mother, a medical researcher sister and a lawyer brother.
-->'''Alex:''' Oh hi Dr. Hofstader!\\
'''Leonard:''' Hi Alex, but please, call me Leonard. ''Dr.'' Hofstader is my father... and my mother... and my sister... and our ''cat''. Although I'm certain Dr. Boots Hofstader's title is honorary.
* ParentalSubstitute: He takes on a fatherly role to Sheldon at times: taking care of his transportation needs, shopping for food and clothing, making sure he goes to bed on time and is often the one he goes to for advice on relationship matters. When he and Penny were dating they served as surrogate parents, when they broke up Sheldon was like a child in a divorce. That led to a lot of DoesThisRemindYouOfAnything dialogue as he and Penny renew their friendship for Sheldon's sake.
* ProudToBeAGeek: Goes back and forth on it (see self deprecation) but at the end of the day he's pretty damn proud of his collectibles and intellect.
* PuppyDogEyes: Used almost exclusively around Penny, not even when dating other women. Heavily lampshaded in the sixth season opener when Penny wanted to talk about her doubts on their relationship but his undivided attention lead her to skipping the discussion and take him to bed as a distraction.
* SelfDeprecation: He's a master at it (though not as much as Stuart or Raj), even joking to Alex about the idea that he'd be a ChickMagnet
* ShipperOnDeck: Clearly supports Howard/Bernadette and Sheldon/Amy.
* TheShortGuyWithGlasses: 5 foot 5 inches (1.65 m), highly inteligent and wears glasses. Befitting the trope. Albeit a protagonist in an OfficialCouple.
* SmartPeoplePlayChess: He plays and in a Season 5 episode, teaches Penny to play. [[spoiler:She beats him in their very first game.]]
* SmartPeopleWearGlasses: He is a highly intelligent man who wears glasses. Although interestingly enough he is the only one out of the main four to actually wear glasses.
* StraightMan: Leonard plays this role, largely for Sheldon's comic lines, and sometimes for funny lines from other characters as well.
* TeamDad: Despite his snarkiness Leonard increasingly becomes this throughout the series, especially the "tough but fair" stereotype, particularly towards Sheldon.
--> '''Penny:''' (to Sheldon) Leonard and I are in a relationship, and occasionally we're gonna fight. But no matter what happens between us, we will always love you. Right, Leonard?\\
'''Leonard:''' (apprehensive) "Always" is a ''long'' time. (they stare at him) Sure, always.
* TookALevelInBadass: Leonard was always one of the more normal and friendly of the group, but in the early seasons he was very timid and strove to avoid conflict whenever possible just because he was too much of a pushover to win. In later seasons, his relationship with both Penny and Sheldon became much more even handed as he isn't as easy to manipulate.
* TotallyRadical: His attempts at being cool usually end up as this, even if the slang is fairly contemporary. His use of phrases like "Later, bro." come across ([[InvokedTrope purposefully]]) awkward.
* TranslatorBuddy: Leonard spends much of his time translating Sheldon's sayings (and explaining his habits) to Penny and other strangers.
* {{Trekkie}}: Like his friends, he loves ''Star Trek'', especially ''Series/StarTrekTheNextGeneration'. He once dressed as Captain Picard for a convention.
* TheUnfavorite: His mother favours his older brother and sister over him. Leonard's brother is a tenured law professor at Harvard University. Leonard's sister is a cutting-edge medical researcher, working with gibbons to cure diabetes. They are more successful in their chosen fields, so their mother considers Leonard her disappointing child. She has published a book with that as its subject.
* UnresolvedSexualTension: Between him and Penny.
* WellDoneSonGuy: Tries to prove himself as a brilliant scintist to his cold mothe. Doesn't help that Sheldon has a closer relationship with her and that she somewhat admitted his siblings' success, but she treats Leonard as some kind of scientific experiment.
* WillTheyOrWontThey: With Penny, although his interest in her is admittedly much stronger. The show built upon the first two seasons of flirting and false starts just to get them officially together in the third. They break up before the end of the season and don't get back together until mid way through the fifth season. They spend the next year or so trying to feel secure enough being together (Leonard's insecure about her attractiveness, Penny's insecure about his intelligence) and once they both come to grips with what they want out of their relationship they get engaged at the end of the seventh season. And even from there their engagement takes time.
* WithFriendsLikeThese: His friend Sheldon shows him no respect, and regularly ridicules his work. Sheldon is also stubborn, selfish and demanding, getting on Leonard's nerves. Leonard still usually goes along with Sheldon's wishes.
* YourCheatingHeart: In Season 5, Leonard has a LongDistanceRelationship with Priya. In "The Good Guy Fluctuation" (Season 5, episode 7)he asks out Alice for a date. Before anything sexual happens, Leonard has second thoughts and confesses to already having a girlfriend,

[[folder:Sheldon Cooper]]
!!Sheldon Lee Cooper, Ph.D.
->'''Played by''' Creator/JimParsons
--> ''I don't understand why in this group [[BlatantLies I never get my way.]]''

Leonard's roommate. A child prodigy, he graduated from college at the age of 15 from East Texas and specializes in Theoretical Physics. Supposedly the smartest of the guys, but he only ends up dominating arguments and debates (both in science and in nerd trivia) because he's too stubborn to quit and resorts to [[InsaneTrollLogic crazy logic]] to win. His dedication to science and geekdom is so complete that he has almost no interest in social skills, regular pop culture (current fads, celebrity gossip, etc) or even romance. He thinks he's superior to... well, to '''everyone'''.
* AccentRelapse: Jim Parsons manages to keep his natural Texan drawl under control but there are a few times it slips out, typically done in character with Sheldon who [[ActorSharedBackground is also from Texas]]. These relapses are rather cleverly worked into the story -- it is heavily implied that Sheldon affects his rather colorless normal accent, and that his natural Texan accent creeps back into his speech when he is too angry or distressed to hide it. One instance when he's drunk:
-->'''Sheldon:''' (drunk off his ass and about Amy) Ain't she great?
-->'''Amy:''' (Embarrassed but flattered) Sheldon....
-->'''Sheldon:''' Now hows about you get us a couple of beers? *smacks her on the butt*
* AccidentalHero: On multiple occasions. For instance, he stopped Leonard from giving up the secrets to the experimental rocket fuel to a spy posing as his date, by barging in and complaining about them trying to sleep together without warning him 24 hours in advance, as their roommate agreement required. He also has a lack of social filter, such as that he will attempt things that others are too timid to do themselves and by all means shouldn't work, but sometimes does. Especially when he nails an ArmorPiercingQuestion on Leonard, it tends to prove beneficial to him in the long run by forcing him to confront that option.
* {{Adorkable}}: Sheldon Cooper, a man who can somehow make wearing a plaid suit almost sexy. There's something endearingly innocent in his total inability to behave like a normal human being.
* AffectionateNickname:
** His mother and sister call him "Shelly", and ''only'' they are allowed to refer to him as such.
** His grandmother calls him "Moon Pie".
* TheAlcoholic: He inherits the gene from his dad, who drank himself to death. It's implied that he's fully aware of it, as he makes a concerted effort not to drink, but on the few occasions that he does, he does not stop.
* AmbiguousDisorder: Sheldon displays symptoms of ''lots'' of different disorders depending on RuleOfFunny.
* AnnoyingLaugh: Whether it's supposed to be his way of actually laughing, or as a sarcastic chuckle for what us lower forms see as "humor", it's annoying.
* AnnoyingPatient: Sheldon suffers from severe social ineptitude, as well as mild hypochondria, making him an absolutely awful person to have around when he becomes [[https://www.youtube.com/watch?v=kZb-LpW-pwM sick]].
* AntiHero: Sheldon is an example of NominalHero; he mostly cares about himself and, intentionally or not, he belittles his friends on a regular basis. He's also arrogant, strict, petty and demanding. Despite this, he does genuinely care for his friends, and a hybrid of that, lack of malicious intent behind his actions, suffering from severe AmbiguousDisorder, child-like traits and multiple PetTheDog moments stop him from becoming unlikeable.
* {{Asexuality}}: Sheldon is conspicuously uninterested in romance, and is one of those rare TV characters whose asexuality is made more or less explicit in-universe.
-->'''Penny:''' I know this is none of my business, but I just... I have to ask: what's Sheldon's deal? Is it girls...? Guys...? Sock puppets...?\\
'''Leonard:''' Honestly, we've been operating under the assumption that he ''has'' no deal.\\
'''Penny:''' Come on, everyone has a deal.\\
'''Howard:''' Not Sheldon. Over the years we've formulated a number of theories about how he might reproduce. I'm an advocate of mitosis.
** He's familiar with the concepts of physical or romantic attraction, but doesn't apparently experience those things himself. Any time he "clicks" with someone in a romantic way, it is always juxtaposed with a common scientific enthusiasm. While the possibility of sexual attraction has appeared from time to time (when Amy kisses him in Season 4, he says "Fascinating", which ''could'' indicate that he found the experience pleasurable or at least interesting), he is written largely as someone who puts intellect and science first and mocks his friends for not doing the same.
--> '''Leonard:''' I can't believe you're going to have Howard choose between sex and ''VideoGame/{{Halo}}!''\\
'''Sheldon:''' No, I'm asking him to choose between sex and ''VideoGame/{{Halo 3}}''. As far as I know sex hadn't been upgraded to include hi-def graphics and advanced weapon systems.\\
'''Leonard:''' Right, all sex has is nudity, orgasms, and human contact.\\
'''Sheldon:''' [[SarcasmBlind My point.]]
** In a Season 3 episode, Penny falls in the shower and breaks her arm. She calls for Sheldon to help, because she knows the sight of her naked would literally do nothing for him. In fact, Sheldon spends more time whining about the possibility of getting injured driving than appreciating the fact that he got to enjoy Kaley Cuoco "in the altogether."
* AttentionDeficitOohShiny: Sheldon usually has issues with maintaining focus when he is unable to work at the university. He goes from one project in the morning to the third or fourth by the time Leonard gets back home.
* BadBadActing: His "Fun with Flags" podcast has him delivering his lines in a monotone and sounds like a speech synthesiser. He also directs his lines directly at the camera, and his body language is cold and uninviting.
* BadLiar: It's virtually impossible for him to lie on the spot, and keeping secrets drives him insane. But if he works up an overcomplicated backstory to the lie then he can manage it okay, but that requires some prep work including falsifying evidence and sometimes a Facebook profile. His trouble is largely knowing when to lie and the significance of lying -- for instance, his intricate preparations would actually be rather good lies for, say, a government intelligence agency...unfortunately, in terms of deflecting attention from a white lie Leonard told to avoid having to watch Penny sing, it was completely over-designed for the situation at hand. He seems to overcome this, as he manages to make up a believable lie on the spot towards Amy in "The Raiders Minimization".
* BerserkButton: He has numerous examples:
** Perhaps it would be best to begin with an in-universe listing...
---> '''Raj:''' What did you do? Did you change the contrast or brightness settings on the television?
---> '''Leonard:''' No.
---> '''Raj:''' Did you take a Band-Aid off in front of him?
---> '''Leonard:''' No.
---> '''Howard:''' Did you buy generic ketchup, forget to rinse the sink, talk to him through the bathroom door?
---> '''Raj:''' Adjust the thermostat, cook with cilantro, pronounce the T in often?
---> '''Leonard:''' No!
---> ''({{Beat}})''
---> '''Howard:''' ...Did you ''make fun of trains?''
** Don't mention Creator/WilWheaton around Sheldon, unless you want a "WHEEEEEAAAATOOOOOONNN!" that would make [[BigWordShout Shatner proud]]. (They made up at the end of "The Russian Rocket Reaction" and are now good friends -- according to Sheldon, anyways). Unfortunately, Creator/BrentSpiner then inadvertently replaces Creator/WilWheaton on Sheldon's Mortal Enemy list.
** The ''WesternAnimation/{{Goofy}}'' character. This is a reference to a 1 panel webcomic strip known as "It's Goofy Time". Sheldon's dialogue is a direct copy of the non-goofy character from it.
--->'''Penny''': What's wrong with Goofy?
--->'''Leonard''': Beats me... he's fine with [[WesternAnimation/PlutoThePup Pluto]].
** Don't sit in Sheldon's spot on the couch. You will regret it.
** While Sheldon is almost fine with cheap shots aimed at his mother, ''do not insult his Meemaw.'' (Grandmother)
** Being let down by his friends, but ''especially'' Leonard, is another one. After Kripke humiliated him on NPR, his misery is compounded when he finds out Leonard laughed.
** Sheldon usually doesn't resort to physical violence, but question the legitimacy of his work and back up your claims with tangible proofs and all bets are off!
** The following exchange:
--->"You want me to share credit?"\\
"[[GetOut GET OUT.]]"
** A minor example, but only his mother and sister are allowed to call him "Shelly". Also, only his "Meemaw" is allowed to call him "Moon Pie."
** Amy is a new one -- Sheldon actually physically assaulted Leonard (via a weak karate chop to the neck), when he felt that Leonard might consider a relationship with her (like Amy, he seemed to be aware that Leonard might rebound with her).
* BetaCouple: Although his relationship with Amy is a complex one, it is significantly more stable then Leonard/Penny. This is accurate to Asperger syndrome (although his attitude to sex is not). If he didn't believe a relationship with Amy would last, he wouldn't bother. Their relationship continues because Amy feels exactly the same way.
* BigDamnKiss: [[spoiler: In the middle of an annoyed rant about romance, the normally very asexual Sheldon ''actually initiates a kiss with Amy'' in "The Locomotive Manipulation." And he ''liked'' it.]]
* BigEgoHiddenDepths: Sheldon may qualify as many of his breakdowns show that underneath his ego, he is in many ways still just a little kid who doesn't understand the world and hasn't recovered from multiple traumatic incidents that occurred during his childhood, he does genuinely care about his friends and several episodes have implied that his ego stems from some sort of coping mechanism (he tries to reason that his childhood bullies hurt him cause they were jealous of him).
* BigGuyLittleGuy: The Big Guy to Leonard's Little Guy. Sheldon is 6' 1" (1.86 m) and towers over the 5' 5" (1.65 m) Leonard.
* BirthdayHater: Sheldon has some mental scars from past birthdays relating to his general aversion to socialization.
* TheBore: Frequently. His flag podcast is incredibly bland and colorless, and he often railroads the conversation onto topics that only he finds interesting (such as railroads). Sheldon, being the way he is, takes the disinterest as signs of his audience's intellectual inferiority.
* BrainyBrunette: A genius with dark hair.
* BreakoutCharacter: The early episodes followed Leonard by default. Since then, the focus has shifted to Sheldon. (Though Leonard's plot with Penny is still the primary plot to follow.)
* BreakTheHaughty: His inflated sense of entitlement and superiority often end up putting him through a thorough, and often well-deserved, HumiliationConga. Subverted in that he never loses his arrogance, no matter how hard he may have been humiliated. He actually faints when Dr. Stephen Hawkings points out a small mathematical error in the paper Sheldon gave him.
* BrilliantButLazy:
** He's certainly very smart and works very hard on things, but has actually accomplished very little, especially compared to Raj and Howard, who have both been at the centre of major stories about their accomplishments. It may be a result of InformedAbility, seeing as his ''offscreen'' resume is fairly impressive.[[note]]He ''has'' won numerous accolades such as the Chancellor's Award, the Stevenson Award (at fifteen!), received an NSF grant, and was invited to present his findings on Bose-Einstein condensates. Also, of all the [=CalTech=] employees on the show (i.e, everyone except Penny and Bernadette), he is furthest up the career ladder -- his job title is Senior Theoretical Particle Physicist, implying that he is the highest-ranked or at least a highly-ranked such scientist on the faculty. Furthermore, in ''The Bat Jar Conjecture'', he was able to match the combined talents of Leonard, Raj, Howard and Leslie Winkle ''on his own''. If he had just been able to put aside his [[FatalFlaw pride,]] he would have won.[[/note]]
** Averted in Season 7. In "The Romance Resonance", he discovers how to synthesize a new heavy element, it doesn't get him mainstream fame but it quickly becomes a big buzz in the scientific community to the point the cafeteria applauded him. [[spoiler:Unfortunately, it turns out that he stumbled across the discovery by accident after misreading a chart and making a mathematical error. And ''then'' it comes out that the team that tested his hypothesis faked their results, so he didn't "discover" anything after all]].
* BunnyEarsLawyer: Averted. It's made clear that, however smart he may be, he's nowhere near as valuable or talented as he thinks and he's been fired with little issue at least once, although comments from President Siebert seem to suggest that there are at least some people on the university board who feel he plays this trope straight.
* BrutalHonesty: Due to his problems with lying, Sheldon normally tells the truth in the most brutal way possible, and then won't realise why they're offended.
* ButtMonkey: Often on the receiving end of a lot of humiliation and punishment. Not that he doesn't bring it on himself, though.
* CallingYourBathroomBreaks: Socially awkward in this department doesn't even begin to cover it.
-->'''Sheldon:''' Around what time in the morning do you have a bowel movement?\\
'''Leonard:''' Er...whenever I need to?\\
'''Sheldon:''' ''*sigh*'' I'm sorry, I'm not renting this room out to hippies.\\
'''Leonard:''' Okay, okay, around 8:00.\\
'''Sheldon:''' Hmm, I can't do that, is 7:30 okay?\\
'''Leonard:''' Yeah, okay, whatever!
* CannotKeepASecret: He either slips into IllNeverTellYouWhatImTellingYou or comes up with needlessly-elaborate lies that fall apart under their own weight. However, if he is given a pre-prepared and reasonably concrete deception he can muddle by.
* CannotTellALie: Whenever he tries to lie, he exhibits incredibly obvious nervous facial tics.
* CantHoldHisLiquor: He almost never drinks casually but it doesn't take much for him to lose it, once getting tipsy after only using tequila as mouthwash. In addition there has been a few times he was unaware of what he was drinking because it was spiked. In Season 7, he begins drinking more commonly at some social events, although he is still not particularly interested in doing so, nor does he seem to enjoy it that much. Never the less his tolerance seems to have increased with his change. Luckily, he's quite a fun drunk.
* CatchPhrase:
** "Bazinga". (Dropped this somewhere around Season Six)
** There's his, "Excuse me!" when he wants to argue a point or just disagrees with something.
** (''Knock, knock, knock'') Penny. (''Knock, knock, knock'') Penny. (''Knock, knock, knock'') Penny. [[InterruptedCatchphrase Sheldon even gets a little annoyed when Penny opens the door before he finishes!]]
** "I'm not crazy. My mother had me tested."
* CelibateHero: As far as being openly contemptuous of any kind of sexual desire.
* CelibateEccentricGenius: At least, before Amy Farrah Fowler came along. Even his dynamic with Amy isn't particularly conventionally romantic.
* CharacterDevelopment: Sheldon hanging out with Penny and the gang leads him to become more and more human. Three particular Season 5 episodes involve him pushing out his personal boundaries, discovering that his rigid scheduling to regulate his life doesn't need to be so inflexible and his life won't collapse if he does things a little differently now and then. Shortly into his relationship with Amy, he was reluctant to keep to his end of the agreements in the Relationship Agreement. In a later episode, when Amy is sick, after some initial hesitation, he agrees to uphold the agreement and take care of her, and does go vigilantly. During Season 6, he notes that he has become more comfortable with physical contact, and admits that someday, perhaps, he and Amy might be physically intimate. In Season 7, he seems noticeably calmer, slyer, and quicker than before.
* CharacterizationMarchesOn: Considering the sheer number of quirks he acquired after the first few episodes, it's somewhat of a shock to see him in the early stages. Sheldon wasn't quite as socially inept or uptight in earlier episodes and may not even have been established as asexual yet. He was still an arrogant jerk, but more of a friend ribbing another instead of having a huge ego mixed with an AmbiguousDisorder. As such:
** Asexuality: He casually refers to Penny being beautiful and immediately recognizes Leonard is attracted to her, seems to (mildly) compete for her attention and when they visit a sperm bank, Leonard makes an off-hand comment that Sheldon is a "semi-pro," the implications in such a context [[ADateWithRosiePalms should be obvious]].
** Social Skills: He advises Leonard that discussing bowel movements isn't appropriate when he invites Penny to lunch. As early as the second episode it becomes a RunningGag Sheldon rarely understands sarcasm. In the first episode, nearly ''all'' of his jokes are sarcastic quips at Leonard's expense. In later episodes, it becomes a challenge to get Sheldon to admit that he's wrong, regardless of whatever outrageous thing he's done or said. In the second episode, although he still believes that cleaning Penny's apartment without her permission was the right thing to do, he offers a sincere apology to her face after some prodding by Leonard.
** Language: His CatchPhrase "Bazinga" did not show up until the late second season. He was also not the first person to use "coitus" as SpockSpeak for sex (that was actually Howard), and in fact simply used the word sex. While he didn't have a potty mouth, he did use swear words [[PrecisionFStrike rather judiciously]] a few times ("Oh gravity, thou art a heartless bitch."), in later seasons he would either censor himself ("I wanted to avoid offending the ho's"), others ("Cockamane?" "I felt uncomfortable with the word Leonard used") or use old fashioned terms ("ninny").
* ChastityCouple: He and Amy agreed there would be no physical relationship, but over time Amy developed into wanting one. While he has no interest in it (and doesn't recognise certain behavior, like helping her bathe and rubbing VapoRub on her chest is arousing to her) he has admitted to her and others that she influenced him and ''he'' considers theirs a deeply intimate relationship even if they aren't physical.
* ChildProdigy: While he definitely was, attending college at 12 and getting his first of two Ph.Ds at age 16, it's possible he's a deconstruction of the concept. His intelligence vastly alienated him from his family, gave him a big ego, made him highly neurotic and socially inept, and though it may or may not be related to his childhood brilliance he's also something of a man-child. He has a journal record of his attempts at potty-training, from the journal itself "April 18 -- This is humiliating, what was wrong with diapers?"
* ChosenConceptionPartner: To Amy, who propositions him for sex under the explanation that it's their duty to sire future geniuses.
* {{Cloudcuckoolander}}: Far too many examples to list.
* CluelessChickMagnet: Sheldon has gained not one, but ''two'' devoted groupies. As well, he ignores a girl who actually ''goes into his room and sits on his bed'', and unwittingly manages to pick up a gay man. After Sheldon ends up charming Raj's date (a successful dentist), causing her to leave for the date with him instead, he then completely fails to understand why he would see her again.
-->'''Sheldon:''' Why would I see her again? I have a dentist. "
* TheComicallySerious: In fact, it's pretty much his entire shtick (aside from neurosis, passive-aggressiveness and love of trains.)
* CommitmentIssues: Sheldon struggles with committing to Amy and then from there moving forward in their relationship. The issue stems from having previously thought of himself as a CelibateEccentricGenius who is above time wasting romantic notions, and having an aversion to change. In one episode, both Leonard and Amy decide to move too fast for their partners and put moving in on the table. Sheldon and Penny are forced to confide their hesitations about it to each other.
* ControlFreak: He regulates when his roommate can use the bathroom. (8:20 am, since you ask).
* CrazyCatLady: Gender inverted. In "The Zazzy Substitution" (Season 4, episode 3), Sheldon and Amy break up. He tries to fill the void in his life by adopting 25 cats. This is treated as disturbing.
* CrazyJealousGuy: If any guy shows minor interest in Amy Farrah-Fowler.
--> '''Sheldon''': *''Karate-chops Leonard''* She is NOT for you!
* CrazyPrepared: His flat is ready for every catastrophe.
* CulturalRebel: He's pretty far removed from the stereotypical Texan he was raised to be. He also affects an accent he perceives to be more educated, slipping back into his native Texan drawl when ''very'' angry or distressed.
* CutenessProximity: Falls into this when he started out naming the plethora of cats after scientists, until he got to Zazzles.
--> '''Sheldon''': I was going to name him Hermann von Helmholtz, but he's so... ''Zazzy''.
* CutLexLuthorACheck: Sheldon's eidetic memory would make him very successful in a variety of conventional career fields, and in one episode we see he's very courteous and helpful when he takes it upon himself to aid customers at a computer store. Too bad he's so arrogant he sees such fields as beneath him and is dedicated to theoretical physics.
* DeadpanSnarker: Further in keeping with the depiction of AspergerSyndrome; this is the type of humour that Aspies are most at home with.
--> '''Leonard''': Sheldon, how could you sit there and let [Howard and Raj] watch my date with Penny?
--> '''Sheldon''': They were clever, Leonard. They took advantage of my complete lack of interest in what they were doing.
* DependingOnTheWriter: The degree of Sheldon's irreligion and views on God seem to be this. While it's clear that he doesn't share his mother's Christian beliefs, he seems to vary between atheism, agnosticism, apatheism and even acknowledging God and/or Jesus' existence at times. [[note]]It's pretty much irrefutable that Jesus existed historically. Whether he was divine or not is [[FlameBait best discussed elsewhere]].[[/note]]
* DirtyCoward: In the episode where [[ItMakesSenseInContext he and Raj were in the steam tunnels]], and he abandons Raj there when some rats show up. Later Raj gives him a WhatTheHellHero speech.
* DitzyGenius: He's a brilliant scientist, but is absolutely, painfully clueless in almost every other aspect of life.
* DysfunctionalFamily: He has several bad memories of his parents fighting and that is reflected in some present events (he returns to being 10 when Leonard and Penny fight). It is commonly implied he grew up in a very unstable home. He also commonly implies or even outright states on occasion that his father was a severe alcoholic. He had a very poor and somewhat abusive relationship with both his siblings. There are some other things where he considered his parents to be AbusiveParents but they were just trying to treat him like a normal child (he wanted a titanium centrifuge for his birthday, [[FelonyMisdemeanor they gave him a motorized dirtbike]]).
* EvilGenius: Sheldon occasionally invokes this on purpose. Leonard has already noted that Sheldon's "one lab accident away from becoming a super villain".
* EvenBadMenLoveTheirMamas: Sheldon's mom is the only one who can override his irrational behavior. He also seems quite devoted to his grandmother, or "Meemaw", as he calls her.
* EverythingsBetterWithPrincesses: Averted. He doesn't go for Amy as Snow White.
* TheFinickyOne: He has a thing for making people sign written agreements, is something of a germaphobe and is very picky about where he sits.
* {{Foil}}: Primarily for Leonard, but can be this for Raj and Howard. Many of his nerdy interests and behavior can be seen as somewhat of an extreme version of the other three. While nowhere near as intolerable as Sheldon, Leonard, Raj, and Howard do show a sense of neediness that can irritate other characters.
* ForScience: The only reason he gives for putting ground-up moths into Leonard's food, claiming it was to determine at what concentration food begins to start tasting "mothy".
* ForWantOfANail: Discussed in "The Cooper Extraction", where we see that Leonard not moving in with Sheldon meant he would've moved in with Raj and not cared about meeting a woman, letting himself go. Without Sheldon, Leonard wouldn't have had a foil to play his awkwardness off of and Penny would've turned him down from the get-go. Amy would've remained a social outcast, miserable and desperately seeking friends. No Leonard and Penny means that Bernadette never gets set up with Howard, who remains with his mother and eventually goes [[{{Psycho}} "Psycho"]] on her. Lastly, without Leonard in the picture to circumvent her [[WMG/TheBigBangTheory theorized]] high sex drive, Penny would've made many advances on Sheldon, likely have given up, then end up settling for a idiot like Zack.
* FourTemperamentEnsemble: The Choleric. He insists on taking decisions for the group, making him the de facto leader, he is devoted to his work, he is a goal-oriented person (who will go to any lengths to achieve said goals), he is typically overconfident, passionate for the things he cares about. He also has the flaws of the type such as being overly Bossy, needlessly stubborn, vindictive, insufferably arrogant, insensitive to the feelings of others, and rude to other people
* FreakOut: The sheer quantity of changes he experiences in Season 7 is too much for him to handle. [[spoiler: They include his new field of work, Leonard and Penny getting engaged, the possibility of Leonard moving out, Stuart's comic book store burned to the ground, him getting more intimate with Amy, the death of Professor Proton and so on...Sheldon goes beyond his breaking point and leaves on a train to straighten his ideas.]]
* TheFriendNobodyLikes: So much that the guys kick him off the team for the Physics Bowl in "The Bat Jar Conjecture". And when Sheldon wants to accept an offer to go on an arctic expedition, they are excited about being Sheldon-free for three months. Penny once asks exactly how he got any friends in the first place and Howard answers that they liked Leonard. In the episode where Leonard, Raj, and Howard are on a camping trip:
-->'''Leonard:''' Too bad Sheldon couldn't come with us.\\
'''Raj:''' Yeah, it's just not the same without him.\\
(Silence for a second and then the three guys start laughing).
* GeekPhysiques: He was described by another character as looking like a praying mantis. The other three geeks also have skinny physiques. It's just that Sheldon's is more pronounced due to being a head taller than the other three.
* GreenEyedEpiphany:
** Season 5 shows that Sheldon has grown very possessive of Amy, if nothing else. When Leonard states that he and Amy had quite a fun time together at a wedding party and playfully threw in sexual innuendo about this "fun time", Sheldon's reaction? A karate chop to Leonard's neck and then:
---> '''Leonard''': Why did you do that?\\
'''Sheldon''': To send a message: She's not for you.\\
'''Leonard''': What?\\
'''Sheldon''': Not! For you!
** Later when Amy begins to date Stuart, Sheldon "officially" upgrades the status of their relationship to boyfriend and girlfriend.
* TheGrinch: Sheldon hates Christmas, claiming it's a knockoff of the pagan celebration of Saturnalia, bemoaning being forced to participate by his zealously religious mother as a child, etc., all to the annoyance of Leonard, who just wants some Christmas cheer because ''he'' was forced to write papers by his family on Christmas. It all comes to a head during a Christmas themed game of ''TabletopGame/DungeonsAndDragons'' where Sheldon leaves Santa (whom they were supposed to be saving) to die, ruining the game and Christmas spirit for all involved. He declares that the real reason he hates Christmas is that Santa never granted him his wish of bringing his "Pop-Pop" (grandfather, and the only family member to encourage his interest in science) back as a kid.
* HardOnSoftScience: [[ExaggeratedTrope Exaggerated]] with him to the point of absurdity. Not only does he regard the social sciences as "largely hokum" (although despite this, he deeply respects Leonard's psychologist mother, however, she's also a neuroscientist), but he also speaks disparagingly of ''other hard sciences'', referring to the geology department as "the dirt people" and having a falling out with Leslie Winkle because she favored supergravity theory over superstring theory. The only non-scientific discipline he has not expressed open contempt for is the law, probably due to his mania with rules.
-->''"I have never said that you [Howard] are not good at what you do. It's just that what you do [Engineering] is not worth doing."''
* HatesBeingTouched: He's terribly awkward about getting close to people, sometimes due to his germophobia and sometimes because he's so bad at showing emotions. In later seasons, he gets a bit better.
-->"It's not a touch phobia, it's a germ phobia. If you'd like to go put on a pair of latex gloves, I'll let you check me for a hernia. "
* [[SheCleansUpNicely He Cleans Up Nicely]]:
** When he has to give a speech, Penny takes him out to buy a new outfit. Sheldon emerges from the changing room looking stylish, dapper and let's face it, handsome, in a black suit. Penny can see how much a decent suit changes his gangly appearance. Sheldon finds the outfit absurd - his usual suit is a garish checked number.
** In Season 6, when Penny gives him a new haircut, Amy is shocked when she sees it and insists that Penny change him back -- because she's worried he might attract other women. "I don't want him walking around like sex on a stick!" (Sheldon agrees. "She's right. I'm too hot.")
* [[HenpeckedHusband Henpecked Boyfriend]]: After a fight with Amy, he has decided to be one to avoid major fights in the future. So when Amy tells [[spoiler:Levar Burton]] he's a worse actor than [[spoiler:Wil Wheaton]] Sheldon tells the former while he may not actually think so, he must agree with Amy. [[spoiler:Levar]] understands completely. This does not normally occur, as he is mostly the dominant one in their relationship.
* HeroicSacrifice: Not a lethal one, but during a paintball war his comrades (Leonard, Howard, and Raj) have no enthusiasm due to prior events, and don't really want to fight. Sheldon proceeds to walk outside, into the open, and take several shots to motivate them into fighting, resulting in victory. [[MundaneMadeAwesome Complete with slow-motion]] and a ''Film/{{Platoon}}''-style [[ShoutOut "death"]].
* HiddenDepths: Sheldon proves to be surprisingly understanding and helpful when hearing about his friends' love problems. He also knows a lot about football, though it's only because his father always made him watch the games as a child, rather than out of his own interest; plus he grew up in Texas, where he mentions that football is inescapable there. Also thanks to his father he is apparently a crack shot with both a bow and a gun. Due to his upbringing, he is also a skilled ballroom dancer and archer. At times, he seems to know more than the other guys about proper social interaction, but his knowledge is shallow and he's ''very'' poor at applying it to real-life situations.
* HilariouslyAbusiveChildhood: Sheldon is revealed to have been so traumatized by his parents' constant fighting when he was a child that he is unable to be around people arguing. He goes so far as to run away from his apartment when roommate Leonard won't stop arguing with his girlfriend. He relates multiple incidents of being bullied (sometimes by his own siblings) that fit the trope, such as discovering string theory, due to being beaten round the head with a book about it.
* HollywoodNerd: A tall, svelte attractive man who is noted by his girlfriend as looking like "sex on a stick" when he gets a more flattering haircut.
* HonorBeforeReason: Will often avoid taking the easy way out of things, though this usually leaves him worse off than before.
* HypocriticalHumor: Often accuses Leonard of being a narcissist and wanting to make everything about him, without a hint of irony.
* InferioritySuperiorityComplex: Sheldon suffers a mental breakdown every time someone proves to be superior to him in science (and once when he was briefly fired in contempt of the new Caltech President), hinting that he latches onto science as his only source of pride and holding massive insecurities about everything else in life.
* InformedAbility: Although the other scientists do have some level of respect for his abilities (Leonard at one point calling him "one of the greatest minds of the 21st century") Sheldon is by far the most fervent admirer of his own intellect, but he frequently makes mistakes (especially in non-scientific fields, sometimes even then) and besides being given an award by the University all his accomplishments are second-hand information. Lampshaded by President Siebert, "The board tells me he has a beautiful mind, but I just think he's bananas."
* InnocentBigot: Occasionally says things that may be considered offensive without realization.
* InnocentBlueEyes: He has large, expressive blue eyes. They may or may not be a physical manifestation of how clueless he is when it comes to social interaction, despite his intellectual brilliance.
* InnocentlyInsensitive: Even when he's trying not to be an InsufferableGenius (usually at the request of one of the other guys), he has a problem of insulting people anyway without realizing it. It's debatable whether or not he realizes how insufferable he really is. Much of his innocent insensitivity stems less from his arrogance and overbearing manner than his total ignorance of social conventions. For example, in one conversation with Penny, he asks her where she currently is on her menstrual cycle. He doesn't understand why it's inappropriate.
* InsaneTrollLogic: Sheldon's thought processes are very alien, and he occasionally purposefully distorts logic to get his way.
** If he cannot have his way or if he manages to fail at an activity then he will often dig deep to find some way to justify why he didn't succeed. After failing at [[DrivesLikeCrazy learning how to drive]] he decided he was an [[EvolutionaryLevels evolved form of humanity]] that was smarter but incapable of driving properly.
** In Season 4, he and Amy play a game called "Counter-Factuals", where they offer a ForWantOfANail scenario where the world is different in some manner, and figure out what the answer to a question is. In this game, Sheldon rationalizes that if a giant beaver ruled the world, it would lead to a chain of events that results in the cheese danish never being invented due to worldwide flooding.
** By the rules of the Roommate Agreement, if he and Leonard vote on something and it's a tie, he settles the tie. Leonard reminds that he voted ''against'' this, to which Sheldon counters he voted "yes", and he settles all ties, so it was a yes.
** Subverted in some other ways. Though some of his lifestyle choices are strange to outsiders, he has well-thought-out reasons for them that make sense, if in a SuperOCD way. For example, [[ThisIsMyChair his spot on the couch]] comes with a list of reasons ''why'' it is his spot, from balanced airflow in the room to allowing maximum interaction with guests (with minimal head turning) while still allowing a proper view of the TV without distorting the image.
* InSeriesNickname: His mother and sister call him "Shelly", though he does not seem to like the nickname. Leonard and Penny have occassionally used the same term. His grandmother calls him "Moonpie", because he is so sweet to her. When Penny uses the nickname, however, Sheldon replies: "No one calls me Moonpie but Meemaw".
** In "The Isolation Permutation", a drunk Amy nicknames him "cuddles".
* InsistentTerminology: He is not a rocket scientist. He's a theoretical physicist! Also, he takes great pains to point out that his team t-shirt spells "The Wesley Crushers" (Those Who Crush Wesley) and not "The Wesley Crushers" (Multiple People Named Wesley Crusher). Dr. Sheldon Cooper would also have you know that he's not crazy; his mother had him tested. She later confirms this (...though she should have followed-up with that specialist in Houston). He also does not play "pranks"; he subjects people to his ''classic'' pranks. He also prefers it when accurate terms are used. One of the more notable things he prefers is to refer to sexual intercourse as 'coitus', probably to separate it from sex as in 'male or female'..
* InsufferableGenius: He's that page's image for a very good reason. Though it's been shown repeatedly that it isn't impossible to outsmart him or even point out mistakes in his work, it's a matter of being stubborn enough to fight him through the insufferable part (StephenHawking notwithstanding).
* ItsAllAboutMe: Though he is able to show concern and attention for his friends on occasion, Sheldon's default attitude is wildly egocentric, taking the view of "the world revolves around me" as an axiom.
-->'''Leonard:''' Sheldon, not everything is about you.\\
'''Sheldon:''' I don't follow you.
* {{Jerkass}}: Explained well by Bernadette:
-->''"He doesn't understand when he's being mean because that part of his brain is getting a wedgie from the rest of his brain."''
* JerkassFacade: While he is often a jerk, he would often rather someone believe he is being selfish than admit he's acting altruistically or with genuine concern for another. Leonard is often the reason for it. When informed that Penny is thinking about ending their relationship, Sheldon confronts her in the middle of the night to talk Leonard up, claiming it is just because he doesn't like change but admitting he doesn't want to see Leonard hurt. Another time he is irrationally concerned about Leonard having a low-risk elective surgery, the lengths he goes to stop it reveals a lot about how much he really does care.
* JerkWithAHeartOfGold: He's insufferable most of the time, but he shows concern and attention for his friends in his own ways, can offer genuinely helpful advice on their problems if he's in the right mood, he's never actively malevolent to them beyond verbal jabs, and is hurt if they slight him in some way. On the other hand, his perspective on social interactions are skewed, so he doesn't understand when he does something offensive or inappropriate, he's constantly flaunting what he considers his superior intellect, and while he can offer helpful advice on a problem at times, he's just as liable to interrupt their explanation of said problem to note he doesn't care. The Heart Of Gold ''is'' there, but it's deep down under a lot of arrogance and an AmbiguousDisorder.
* KindHeartedCatLover: When he and Amy disagree over the superiority of physics vis-a-vis neurobiology, they terminate their friendship.[[note]]Sheldon's mother manages to bring them back together in the end, thanks to a little judicious reverse psychology.[[/note]] He fills the void left by her absence by adopting a plethora of cats. His mother also sings him his sick song, "Soft Kitty" whenever he's sick, and so does Penny. Sheldon even sings it to her at one point.
* KnowNothingKnowItAll: Sheldon tends to lapse into this when he veers away from physics and into the life sciences. Sheldon acts like he knows United States history when he doesn't. He tries to convince Leonard that he should be a history professor instead of a physicist by testing whether Leonard knows that slavery in the United States ended in 1863. It didn't. At the Renaissance Fair, when he complains about the historical inaccuracies, but doesn't realize Leonard's knight costume is at least 200 years out of date. His "defense" to a charge of running a red light in "The Excelsior Acquisition" shows he knows absolutely ''nothing'' about the law, as well. On similar lines, his beloved Roommate Agreement is full of loopholes, and doesn't stand up to the scrutiny of a legal professional. Many of his beloved factoids, when outside the sciences, are actually common misconceptions: The Romans did ''not'' sow over Carthage with salt, for instance, as any archaeology undergrad could have told him. However this is often a case of DependingOnTheWriter, sometimes he is presented as being as smart as he thinks he is (or at least knowledgeable in a broad range of area's). The Rule (following the RuleOfFunny) often seems to be that he only slips into this whenever it would actually benefit him not to.
* LackOfEmpathy: {{Subverted}} Although he often comes across as this Sheldon is perfectly capable of feeling empathy and can even be quite caring on occasion. Its just he's very bad at showing it.
* LikeBrotherAndSister: Towards Penny.
* LimitedWardrobe: Almost always wears short sleeved t-shirts with a longer shirt underneath, rolled up to the elbows. Superhero t-shirts are the most common, GreenLantern (or a symbol of one of the other Lantern Corps) and TheFlash especially. This leads to a rather amusing variation of CharacterizationMarchesOn, as in [[http://the-big-bang-theory.com/gallery/picture/274/ one early episode]] he follows the general pattern, but it's far removed from what he was later known for.[[note]]Interestingly enough, the color combination is that of classic Silver Age Lex Luthor's power armor, so maybe they went for the "evil genius" look.[[/note]]
* LiteralMinded: More than everyone else, being SarcasmBlind.
* LittleKnownFacts: Loves bringing them up in conversation, sometimes to benefit himself such as why he should have the last dumpling, because in Tia culture its reserved for the most valued member of the group.
* MadScientist: Has about as many shades as you can get while still being thoroughly grounded in reality. A brief list of examples is his willingness to try electric shocks to modify Penny's behavior by negative reinforcement, the government monitors his computer activities due to his efforts to hack their systems, as a child he attempted to build a "death ray" and to create a griffon by cross-breeding lions and eagles, and he occasionally makes references to societal reforms he plans to implement when "[he] comes to power". Lampshaded by Leonard, who notes Sheldon is "one lab accident away from becoming a supervillain."
* ManChild: While all the characters indulge themselves in childish things, Sheldon insists that ''someone'' take care of him the way his mother would when he's sick (or even just ''home''sick), locks himself in his bedroom where no one else is allowed when he's furious, curls up into a crying ball of sad on his bed when he's embarrassed, runs away from home when he's upset, is practically traumatized by the sound of people arguing[[note]]Although this one may be perfectly justified, as his parents often got into arguments when he was a child and it is also implied that a lot of the arguments were exceedingly violent (he mentioned that his father would start throwing plates and shattering them in the kitchen, and that his mom planned to place glass shards in his father's meatloaf), even when they said to Sheldon that they stopped fighting[[/note]], and is stubborn and petty beyond all reason. The only thing on this planet that can force him to behave rationally when he's angry or depressed is an order from his mother, who Leonard calls "Sheldon's Kryptonite". He also responds positively to being patronized by Penny, especially if he gets a toy robot and a comic book out of it. [[LampshadeHanging Lampshaded]] by Bernadette at one point, after she successfully got him to go to bed by first reasoning with him about the effects of lack of sleep, and then simply treating him like an overgrown child and sending him to bed.
* ManipulativeBastard: Although failing on most of his attempts in the first few seasons, starting Season 6 and appearing more commonly in Season 7, Sheldon begins to get more successful at his attempts to manipulate others, learning how to play off of their weaknesses to his advantage.
* MeaningfulName: Named for television producer Sheldon Leonard and possibly for physics Nobel Laureate Leon N. Cooper.
* MinorInjuryOverreaction: His response to getting a cut on his thumb? He faints.
* MommasBoy: His mother still treats him like a child and is the only person who can tell him what to do.
* MoralityPet: His mother, Amy and sometimes Penny.
* MotherNatureFatherScience: A rather blatant example with Amy, who's a biologist and him a physicist.
* {{Narcissist}}: The most fervent admirer of his own genius.
* NeatFreak: He broke into Penny's apartment to clean, because being that close to mess made him have trouble sleeping.
* {{Nerd}}: His life is almost exclusively devoted to the nerdy interests of science, science fiction, fantasy, comicbooks, and videogames.
* NeverMyFault: Which makes those rare occasions (see PetTheDog below) when he ''does'' admit his own fault even more significant, such as when he accidentally [[spoiler: cost Howard his security clearance, leading to his career suffering a serious setback.]]
* NoSenseOfHumor: Zigzagged. Sheldon has a sense of humor, but it's so separate from everybody else [[StrangeMindsThinkAlike (except for Amy)]] that he doesn't get most jokes and most people don't get his. ''And'' he always explains his jokes.
* NoSocialSkills: To the point where Sheldon seems to consider "accepted social protocol" more like inviolable laws he ''must'' obey, rather than doing nice things simply because he's trying to be ''pleasant''. Lampshaded a few times by Penny.
* NotSoHarmlessVillain: Although rarely a true villain, when ever he does take an antagonistic role its normally either as a petty prankster seeking revenge or a egomaniac control freak whining to others when he doesn't get his way. However in "The Itchy Brain Simulation" he proves he when he's had time to plan he can be quite impressive. He successful manipulates his own best friend into simulating OCD, and torturing himself, all while barely lifting a finger. He is certainly smart enough to plan some extremely potent revenge schemes but he tends to fail or go sideways in execution (a prank against Kripke involving a fast expanding foam ended up being sprung when members of the board are visiting his office).
* OOCIsSeriousBusiness: The few times he deviates from specific idiosyncrasies is treated as exceptionally odd and results in some big reactions from the characters, notably how Penny started crying when Sheldon gave her a hug for the Creator/LeonardNimoy Napkin Christmas gift.
-->'''Leonard:''' Between Sheldon giving up [[ThisIsMyChair his spot on the couch]] and you (Penny) [[InstantExpert playing chess like Bobby Fischer]], I would guess that someone went back in time and stepped on a bug, changing the course of human events.
* OmnidisciplinaryScientist: Sheldon, a string theorist who on his days off also dabbles in, for example, genetic engineering, and who purportedly built a nuclear reactor and a "death ray" as a child, not to mention his extensive knowledge on the Social Sciences (History, Political Science and Flags) as well as basic Notary Law (he's the principal author of the Roommate Agreement with Leonard and the Relationship Agreement with Amy). That being said though, it [[DependingOnTheWriter depends of the writer]], as we've also seen Sheldon unable to ascertain how to open a toolbox and much of his [[KnowNothingKnowItAll supposed]] knowledge of [[HollywoodHistory other]] [[HollywoodScience fields]] is either inaccurate or flat out wrong.
* OutOfCharacterMoment: His obsession with cleanliness was evident early on, with him cleaning Penny's apartment himself while she slept and later panicking when he hears she came from a family gathering where they were sick. In the Season 1 episode "The Loobenfeld Decay", he places a bag of chicken in a take-out container into an outside bin, then recovers it a few minutes later with [[RuleOfFunny nothing more than a quick blow]]. It certainly stands out as an anomaly with his regular behavior.
* PetTheDog: He's typically very selfish and insufferable and frequently comments on how much he hates social interaction even with his closest friends. But there are a few rare moments where he actually uses his selfish behavior as a smokescreen to hide that he's actually concerned and/or happy for his friends, but doesn't want to admit that right out. For instance, he discovered through Amy that Penny had some doubts about her relationship with Leonard. So he confronts her late at night and tries talking Leonard up, saying that he just wants to keep the status quo for his own sake. As the conversation went on, he eventually asked with sincerity, "Please don't hurt my friend."
* PhotographicMemory: He has it, though he objects to the name and insists that it's properly called eidetic memory. He's able to recall the precise date and time of any event in his life and win complex card games through memorization
* PolarOppositeTwins: With Missy. Sheldon is wildly egocentric, only interacts with others when forced to and tends to look down on anyone who isn't as smart as he perceives himself to be. Missy is out-going, friendly, level-headed and sociable. Sheldon points out that non-identical twins will only resemble each other as much as siblings born on separate occasions.
* {{Pride}}: A lot of the problems he encounters could be avoided if he wasn't so arrogant and proud. A good example is "The Excelsior Acquisition", where he tries to fight a traffic violation on principle when a scene just before he finds out about his summons establishes he has several thousand dollars in uncashed paychecks.
* ProudToBeAGeek: Sheldon simply refuses to be anything but a geek and unlike his friends (mostly Leonard) he isn't embarrassed at all by his geekiness.
* RailEnthusiast: A fan of model railways, he even wears his own pretend-Engineer's hat. This would be rather sweet if he didn't neglect Amy for it, something which visibly offended her.
* RaisedCatholic: Was raised in East Texas by an [[HolierThanThou overly-religious]] Christian mother, but he himself does not partake in religion. Though it is unclear whether he is an atheist, agnostic, NayTheist, etc.
* TheRainMan: To an extent. His intelligence verges on SuperIntelligence, making him able to achieve prominence in his chosen scientific field. At the same time, though, it contributes to his weirdness and failure to connect with people. Even Sheldon's family and his few friends have trouble understanding and tolerating him.
* RuleOfThree: His [[http://bigbangtheory.wikia.com/wiki/Sheldon%27s_Knock characteristic knock]] on the door is a RunningGag. Three knocks, followed by calling the name or names of whoever is on the other side of the door (Penny, Amy, Bernadette, etc). Followed by a second set of three knocks and another call of the name/s. And finishing with a third set of three knocks and another call of the name/s. When the door opens before Sheldon has a chance to complete his ritual, he simply continues knocking the open door.
** There a few minor deviations of the general rule. In "The Toast Derivation", Sheldon does not call Leonard, Howard, and Raj by their names, using the phrase "all my friends" three times. In "The Anxiety Optimization", Sheldon does not call Penny, Amy, and Bernadette by their names, using the word "ladies" three times.
* RulesLawyer: Provided they're either rules he drafted himself or those governing the playing of TabletopGames. As Priya and "The Excelsior Acquisition" showed, he doesn't have a very good handle on the actual law. Though it is likely his arrogance plays a part in this. He was able to match her on his second try.
* SacrificedBasicSkillForAwesomeTraining: Sheldon is such a ChildProdigy, that he entered college at age 11 and graduated with honours at 14. He has devoted pretty much his entire life to research since then, and this may have contributed to his lack of rudimentary social skills (such as not gloating at a judge) and his overall inability to deal with the mundane world (germophobia for instance).
-->'''Leonard:''' Sheldon's in jail?! For what?\\
'''Penny:''' For doing the same crap he always does, except to a judge.
* SarcasmBlind: ZigZagged. He understands the concept of sarcasm and can use it himself, but almost never picks it up when it's about him. He gets lucky once and a while, but it seems like guess work on his part. Leonard even made a sarcasm sign in an early episode. And Sheldon keeps track of how many times he correctly understands sarcasm. Once, when Howard made a sarcastic comment, Sheldon asked "Was that sarcasm?", and Howard sarcastically replied "No!" — which, of course, Sheldon failed to recognize the sarcasm of.
** In at least one episode, this is inverted: Sheldon takes something as sarcastic when it isn't.
* SesquipedalianLoquaciousness: Uses lots of big words, even when it's not necessary.
* ShesNotMyGirlfriend: Amy. In his own words: "She's a girl and she's my friend, but there's [[NoHuggingNoKissing no touching or unsanitary exchange of saliva]]." Finally subverted in Season 5, where while Sheldon holds to the ban of physical intimacy, he and Amy are "officially" together, as noted by the Relationship Agreement he drew up.
** As of Season 7, occasional kissing seems to have entered their relationship. Presumably the exchange of saliva is highly sanitary.
* SiblingYinYang: Missy and him couldn't be more different despite being fraternal twins.
* SignatureLaugh: A sort of quick inhalation sort of thing.
* SingleTargetSexuality: Amy is the ONLY person he has ever expressed romantic feelings towards. While other women (and men) have shown some form of attraction to him the most he ever reciprocates is an appreciation that they appreciate him. Even though a sexual relationship is still repulsive to him, he confessed to Amy that the two of them is the most intimate relationship he has ever had.
* SmallNameBigEgo: Played With check "KnowNothingKnowItAll". He believes himself to be multi-talented when his only real skill is in theoretical physics but this does fall in to DependingOnTheWriter as he sometimes genuinely is near to as smart as he believes he is and has shown in-depth knowledge of other subjects and his friends do on occasion acknowledge that he really is the smartest of them. He's also very unaware of how much people dislike him and can't understand why they wouldn't want to spend time with him. But of his friends he is the most successful (being the Senior Theoretical Physicist at Caltech) and is apparently held in high regard by the physics community. Never the less its made very clear that he doesn't live up to his opinion of himself.
* SmartPeoplePlayChess: He and Leonard play three-dimensional chess (yes, it does exist). He also created 3-man chess, complete with new pieces. Unlike many of his socializing-related projects, his new rules are seemingly enjoyable and not over-complicated.
* SmugSnake: Very smug about his genius-level intelligence. He sometimes talks about himself as a new and improved human. Ironically he can often live up to his claims, its purely down to his ego that he fails.
* SocialDarwinist: As shown when his guided meditation gets sidetracked by imagining Franchise/{{Godzilla}} attacking ''VideoGame/SimCity''.
--> '''Sheldon''': People of [[{{Egopolis}} Sheldonopolis]], this is your Mayor! Follow me and I will lead you to safety. If your children cannot run, ''leave them behind!''
* SouthernFriedGenius: Subverted for the most part. Despite hailing from Texas, he displays none of the traits that are typically associated with the "redneck" aspect of the trope. This is apparently a conscious decision as it shows up when he's very upset.
--> "No one calls me Moon-Pie but Meemaw!"
* SpockSpeak: Just let this example speak for itself:
--> '''Sheldon''': Well, I'm polymerized tree sap and you're an inorganic adhesive, so whatever verbal projectile you launch in my direction is reflected off of me, returns on its original trajectory and adheres to you.
* SpoiledBrat: Sheldon tends to embody this trope, often getting whatever he wants, how and when he wants it, no matter how unreasonable, merely by being extremely difficult. Ironically, his family seem to be the only people not enabling him.
* StaticCharacter: Justified; he [[EnforcedTrope makes an active effort]] to not change himself.
* SuperOCD: Don't sit on his favorite couch cushion, you'll smush it out of shape. A good example is when the cushion that was "his spot" on the sofa was stained and he spent the time in which the cushion was being cleaned slowly going crazy, eventually going to the point where he was crouching over the spot where he used to sit. Howard tries to solve the problem by grabbing Rajesh's cushion and placing it in Sheldon's spot. Rajesh starts to complain, giving us:
-->'''Howard:''' Who cares where you sit? ''You are not crazy!''
** In the thirty seconds it took Rajesh to find a new place to sit, Sheldon had found something unacceptable about the new cushion and the fun was restarted.
-->'''Sheldon:''' These shrimp are all the same size, there's no logical order to eat them in. [chucks them into the garbage can]
** Sheldon always has to knock on Penny's door 3 times and each knock is followed by him calling Penny's name. Penny at one point tries to mess up Sheldon's rhythm by opening the door and imitating what Sheldon does. He feels "that's just wrong."
* SurroundedByIdiots: ''His'' opinion of everyone around him.
* TookALevelInJerkass: In "The Itchy Brain Simulation" he goes from a merely annoying InnocentlyInsensitive {{Jerkass}} to an EvilGenius MagnificentBastard.
* {{Trekkie}}: ''Star Trek'' is one of the group's favourite franchises. They especially dig ''Series/StarTrekTheOriginalSeries'' and ''Series/StarTrekTheNextGeneration'. Spock is Sheldon's favorite character.
* {{Troll}}: He's often guilty of this behavior, as demonstrated by most of his "Classic Pranks", his heckling of both Leonard and Brian Greene's lectures and when his [[RunningGag continual swiping]] of the One Ring from Leonard.
--> '''Howard''': You're not helping!\\
'''Sheldon''': I'm not trying to help! *''Smirks''*
* {{Tsundere}}: Type A platonic version towards Leonard. Although he constantly mocks Leonard for being a less-intelligent Experimental Physicist, he has constantly proven that he cares greatly for him.
* TwitchyEye: Gets a very prominent one when he either ''doesn't'' know something, or the others don't let him finish explaining something.
* TVGenius: This is a huge part of the sitcom's premise. Leonard, Raj and Howard are also extremely intelligent, but no where near as TVGenius as Sheldon. To reiterate, in a show where five of the seven main characters have at least one doctorate (Penny has a high school diploma, while Howard only has a masters) and most of the recurring characters are university professors or otherwise in highly technical fields, Sheldon is universally regarded as bizarre. Not incomprehensibly so, however, as he literally came with a manual. That he himself wrote in PDF format and hands out to new friends.
* {{Ubermensch}}: Sheldon has a slight disregard[=/=]disapproval of certain social protocols, his obsessive-compulsive behaviors are often seen as weird or overdone by his friends, and he outright considers compassion and understanding to be a limitation to himself. Despite all of this, Sheldon is an ''incredibly'' intelligent genius physicist, and it can't be denied that his zealous imposition of order on his household really does help himself as well as Leonard, despite his protests.
* UnclePennybags: Surprisingly -- Sheldon's lifestyle is very low-budget and he saves his money, to the point he feels perfectly comfortable giving Penny enough money to both pay her rent and fix her car when it breaks down. Despite her assumption that Sheldon's obsessive tendencies would lead him to hound her, it turns out that he's incredibly lax when it comes to lending his money. He honestly doesn't care ''when'' it's paid back, as long as it ''eventually'' is.
* TheUnsmile: Masters it and is even the page image.
* UnsympatheticComedyProtagonist: Sheldon's self-centered egotism and condescending behavior is the source of conflict for any given episode, even just by being sick and asking for help (his obnoxious neediness at that stage is dreaded by everyone).
* VerbalTic: Sometimes refers to things with unnecessary tautologies, such as "''Franchise/GreenLantern'' Lantern", or "''[[Literature/TheLordOfTheRings Lord of the Rings]]'' Ring".
* VirtueIsWeakness: He actively believes that being compassionate and open-minded is a weakness, to the point that he (unsuccessfully) attempted to break up with Amy when he realized her effect on his personality.
* WackyGuy: Has a tendency to come up with strange ideas and plans, which affect everyone around him. Such as trying to stay awake for days (to work on a scientfic problem), stepping in into the roles of busboy and waiter at the Cheesecake Factory without bothering to notify his new employers, tracking down Creator/JamesEarlJones to convince him to co-found a comic book convention, etc.
* WithFriendsLikeThese
-->'''Sheldon:''' Those are traits associated with a psychopath.\\
'''Leonard:''' Are you worried about me killing you in your sleep?\\
'''Sheldon:''' No, I imagine if you were going to do so, you would have done it years ago.
* WhoopiEpiphanySpeech: Played with. While such a speech is usually one of great wisdom made by someone who isn't all that educated or book smart, it can't be said that Sheldon is either of those things. But he ''is'' very socially inept. So it comes as a surprise at times when Sheldon has rare gems of social wisdom (albeit wrapped in SesquipedalianLoquaciousness) that give Leonard new insights he couldn't see before.

->'''Played by''' Kaley Cuoco
-->You know where I was all afternoon? Auditioning with 50 other blondes for an anti-depressant commercial... They said I was too perky...

Nebraska-born neighbor of Leonard and Sheldon, moved there in the pilot. She aspires to be an actress, but to pay the bills she works as a waitress at the Cheesecake Factory. Initially friendly but distant to the guys, she grew to become OneOfTheBoys. She has an slightly below average intelligence which is overshadowed by being around these super-geniuses, but displays common sense and social awareness that the others almost completely lack. Her relationship with both Leonard and Sheldon opened her up to the concept of higher thinking and she has found some difficulty going back to keeping "regular" people as company.
* AbsoluteCleavage: Most of her tops plunge right into this, especially in the earlier seasons. Also of note, her "secret weapon" dress.
* ActionGirl: For the standards of the series. She tends to show the four nerds [[GroinAttack how issues are solved in Nebraska...]]
* TheAlcoholic: The hardest drinking member of the cast. Typically manifests with her finishing the bottle while everyone else is on their first glass, it can be inferred that she is accustomed to heavier drinking company and so when with a bunch of recreational drinkers she stands out more.
* AllGirlsWantBadBoys: Has a ''bad'' case of this. Notably, she identifies the qualities she likes in men as "macho, handsome, success, money", not necessarily "badness." When hanging out with Leonard as JustFriends, he realized he didn't have to conform to what she wanted and became assertive about their activity leading to some obnoxious behavior. She later admitted that even though things got out of hand she ''liked'' seeing him take charge for once.
* AllGuysWantCheerleaders: A 20s-30s version with her and the guys in the core group, she was very popular in high school.
* AllWomenLoveShoes: She has a large collection of shoes, despite being in a poor financial situation.
* TheAtoner: The plot point for a Season 5 episode. She attempts to put things right with those she hurt in her high school days. None of them want to listen. In Season 7, she realized that Leonard was always the one to do romantic gestures and the only thing she offered in return was sex. She took the time to plan out a special evening in return.
* BadBadActing: Zig-zagged, along with HollywoodToneDeaf. We see her in a hemorrhoid commercial and an unreleased movie from before she met the guys and her acting is shown to be pretty stiff and unnatural, but it is meant to reflect on the quality of the product rather than her talents as an actress. But we see her as Blanche in a student production of ''Theater/AStreetcarNamedDesire'' and she performs the role well (considering we only see a snippet, if she was more intense it would look odd in context), and was praised for being very natural and comfortable on Sheldon's web series.
* BatterUp: It's implied in one episode that her WeaponOfChoice is an aluminum bat.
* TheBartender: She works as a bartender while WaitingForABreak.
* BeautyEqualsGoodness: She initially seems to believe this. The scales fall away pretty fast.
* BerserkButton:
** One thing that definitely sets her off, especially hanging around these geniuses, is being implied that she is stupid.
** She's not very tolerant of Howard's sleazy comments, either.
* BetterAsFriends: She feels that things are easier with Leonard as friends rather than as a couple, though their attraction to each other hasn't ever wavered. They got together early Season 3 and broke up towards the end. Nearly two seasons later, they decided to try experimenting being together again using a UsefulNotes/{{beta test}}, given that they never stopped caring for each other.
* BookDumb: Even by normal standards, she's pretty clueless when it comes to anything academic. [[BerserkButton But don't tell her that.]]
* CatFight: In one instance with Alicia, an {{Expy}} of her that was taking advantage of the boys' kindness.
* CharacterDevelopment: In the first season, she was friendly with the group but didn't really hang out with them much. By the second season, she started to consider them to be some of her best friends and was even retaining some of the scientific principles the others would explain to her. After getting together with Leonard and later breaking up, she found that she couldn't go back to dating dumb guys again. In later seasons she slowly starts trying to further her own education. She takes a couple of college classes and moves from a WishFulfillment acting career into a more stable job as a pharmaceutical rep (one that requires more studying than she has ever done in her life). She has also accepted that while she'll never know exactly what Leonard does, she appreciates his intelligence and takes the opportunity to write down words to memorize so she can at least ask him how his experiments are going.
* CharacterizationMarchesOn: Penny was a lot dumber initially (for example, claiming her screenplay isn't based on her life because she's from Omaha and not Lincoln). She quickly moved from TheDitz to WomenAreWiser. Though this may be that she has gotten smarter from hanging around the guys. In a flashback as a teenager, it shows Penny celebrating a negative pregnancy test in quite a ditzy manner. Though there are some areas she is still clueless about such as thinking Vegas wedding chapels are for pretend weddings though this is likely because something of that nature never came up in conversation.
* ClosetGeek: Becomes one as the series goes on, to the point of watching the ''Film/StarTrek'' movie before one of the guys and getting into an intense argument with the girls over [[ComicBook/TheMightyThor Thor's hammer]]. She does deny a lot of her geekiness once assuring Amy there was no difference between Star Trek and Star Wars despite it being clear she knew otherwise. She does openly admit to liking ''Series/GameOfThrones'' watching it on her own without Leonard urging her
-->"Nah I like that show. It's got dragons and people doing it"
* CloudcuckoolandersMinder: Shares Sheldon wrangling duty with Leonard. After Sheldon came back from Disneyland, the two of them even looked on affectionately as he slept afterward as though Sheldon were their son.
* CommitmentIssues: Penny has this problem, ''big time''. She and Leonard eventually works through it by Leonard putting the power to propose marriage in Penny's hands, so she won't have the weight of it on her shoulders until she decides she's ready. At the end of season 7 they mutually agree to get married. though she seems to be in no rush to get married claiming she wants to prove to her mom she's not pregnant.
* CoolBigSis: Once she fully integrated into the group, she likes hanging out with guys and they with her. She's later very sisterly to Amy and Bernadette.
* DatingWhatDaddyHates: Her more common boyfriends were, according to her dad, "skateboard idiots, white rappers, and sweaty dumbasses with their backwards hat." This makes him very pleased to see her dating Leonard, a NiceGuy who is college educated, has a steady job, and no felonies on his record.
* DeadpanSnarker: Has increasingly evolved into snarking as the show continues, mainly towards Sheldon, more than likely a result of of his verbal abuse.
* DoesNotLikeShoes: In general, she is the character most frequently seen barefoot. She makes an exception for flip-flops. A point is often made about [[AllWomenLoveShoes how many shoes she buys]], yet she never actually seems to wear them.
* DownOnTheFarm: Penny's from just outside of Omaha.
* DrivesLikeCrazy: Penny does not actually drive badly, she drives like a person who has driven for a very long time and will sometimes bypass 'normal' behavior for a quicker route, such as not slowing down much over speed bumps. Her constant ignoring of the Check Engine light is a running gag, though.
* DrowningMySorrows: Whenever she has a problem, she usually reaches for the nearest wine bottle. Particularly prominent in The Flaming Spittoon Acquisition, where in nearly every scene she's in, she has a glass of alcohol ready, mainly because she was still upset over Leonard and Priya.
* DumbBlonde: In the early episodes, she seemed to be a [[TheDitz ditz]], but [[CharacterizationMarchesOn as the series progressed]] she showed average-level intelligence and a knack for pop culture. She's still dumb if you compare her to the boys, Bernadette, and the resident {{Brainy Brunette}}s Amy and Leslie, but given all of those characters are explicitly stated to range from [[OvershadowedByAwesome above average to abnormal intelligence]], a straight-up comparison seems unfair.
* DysfunctionalFamily: The few mentions of her siblings indicates she comes from one. Penny's sister shot her own husband while drunk. Penny's brother practices clandestine chemistry, working in a meth lab.
* EmbarrassingTattoo: Penny has one on her buttock she claims is the Chinese symbol for "Courage". According to Sheldon, it actually means "Soup".
-->'''Sheldon:''' But I suppose it does take courage to demonstrate that kind of commitment to soup.
** She apparently got a hidden [[Series/SesameStreet Cookie Monster]] tattoo some time in the two years she and Leonard were broken up. When they got back together she told him that his reaction to it must either be nothing or "awesome!" Although another responsible reaction was Leonard inhaling sulfur hexoflouride (the stuff that makes your voice get really deep) and imitating the Cookie Monster.
* EvenTheGirlsWantHer: It's a RunningGag with her and Amy, although Bernadette doesn't share this.
** In Series Eight, she casually relates that her high school PE coach "liked her too much" and furthered the young Penny's pastoral development by taking her to a Melissa Etheridge concert. Penny apparently got straight A's from her somewhat infatuated teacher, but does not disclose [[SexForServices how far she had to go to get the A's]]. apparently "it all worked out just fine".
* TheEveryman: She could be considered this since she's the only main character who's not a super genius.
* EveryoneLovesBlondes: All the guys on the show are into Penny to some extent, except for obviously Sheldon.
* TheFace: Besides being the only female lead, Penny is the only one of the five who is not a socially incompetent nerd.
** TheChick: Again, she's the only female lead.
** TheBigGuy: She's more capable of handling herself on a physical level than the guys are.
* FatalFlaw: Fear of commitment is arguably her defining flaw in the series. Due to this she's [[spoiler: broken up with Leonard]] at least once and has insecurities about the prospect of [[spoiler: marrying him]]. To a lesser extent she shares Leonard's insecurity, hers being more about whether she's intelligent enough for him.
* FeminineWomenCanCook: Averted, her "special" ingredient for the ramen she served for her and Leonard's date night was the flavor package.
* FourTemperamentEnsemble: There are only three women in the ensemble, but Penny is the Choleric. She is the de facto leader of the group, and its strongest member, fairly independent from her significant other, and practical. She also has flaws associated with the temperament, such as having a nasty temper, being vindictive, and rather insensitive.
* GamerChick: Has shades of this with her ''VideoGame/AgeOfConan'' addiction and swift mastery of ''Franchise/{{Halo}}'' multiplayer. Not to mention her defeat of Leonard at chess (the same day she learned the rules!) in Season 5.
* GeekyTurnOn: She's gained a better appreciation for science and [[NerdsAreSexy throughout the series has progressively started to find Leonard's ''intelligence'', not just companionship, genuinely sexy]]. It's best shown in "Holographic Excitation" when, after some prodding from Amy and Bernadette, she visited Leonard at work (she hadn't visited before partially out of intimidation). After he showed her some holograms he was working on she was so amazed by that side of him they fooled around in his lab.
* GirlNextDoor: She moves into the apartment across the hall in the first episode and that alone gave Leonard some hope that she might become interested in him. She is consistently portrayed as a fairly down-to-earth and friendly girl who helps fill in the gaps in the guys' social skills.
* GirlyBruiser: Penny is an attractive, outgoing, and quite boy-crazy aspiring actress. However, she's incredibly strong for a woman and way more capable of handling herself on a physical level than any of the guys on the show. In one episode, she actually broke Howard's nose with just one punch. In another, she wrestled Sheldon to the ground in a second.
* GoodBadGirl: Although she's a nice girl, she does mention she started dating at ''14'', and she was going to sleep with Stuart when they went on a date, until Sheldon unintentionally interrupted. An early episode had her casually admit that after every breakup, she engages in thirty-six hours of meaningless sex with a random guy. In a ''thirty-seven hour time frame''. There's also a flashback of her as a teenager reacting with ecstasy at a negative pregnancy test.
* GroinAttack: She doesn't appreciate people stealing Sheldon's "stuff", and a swift kick to the balls is her preferred method of dealing with them. This is apparently the way they handle such issues in Nebraska, although a baseball bat appears to be an option as well.
* HairOfGoldHeartOfGold: In the early seasons, Leonard (and later seasons Amy) idealized her as someone pure and innocent, exemplified when he consoled her after a bad incident at a Halloween party. While she is undoubtedly a very sweet and friendly person, she carries her own issues with a mean, angry, or stubborn streak, and Leonard acknowledging that she was imperfect and their relationship was imperfect was seen as a turning point for the better.
* HardDrinkingPartyGirl: Has these tendencies, especially when she's depressed or disappointed.
* HeelRealization: In Season 5, she realizes that she was a bully in her high school days, and attempts to make amends with those she hurt, with little success. A variation happens in Season 7 when it's pointed out that she never took the time to do something romantic with Leonard (and sex doesn't count). She never had to put much effort into relationships because she was pretty enough that guys just flocked to her.
* HeroicBSOD: A minor one, she had a personal crisis when Leonard tried to get her interested in ''Series/BuffyTheVampireSlayer'', figuring it was the one show they would enjoy together (cheerleader premise, girls kicking ass and Creator/JossWhedon's witty writing) and he was devastated that she just thought it was okay. It caused her some serious introspection because she realized that she lacked the same enthusiasm for really anything, worrying that she was holding back on appreciating things in her life. She got out of it by realizing how much she loves being with Leonard and the group and seeing ''their'' enthusiasm for all these nerdy things.
* HiddenDepths: There are a few occasions when she surprises even herself with retaining scientific principles, thought experiments and nerd culture just from hanging around these guys. She memorably did a double-take after using a ''Franchise/StarTrek'' analogy. She started to freak ''herself'' out when she got all the references at the guys' "Star Wars Day Breakfast" on May 4th. She was also familiar with the mythology of ''Series/DoctorWho'' from watching it with Leonard despite her best efforts to not care.
* HollywoodToneDeaf: An early episode had her practicing for a musical performance, when overhearing it Sheldon remarks "[[{{Metaphorgotten}} If cat's could sing... they'd hate it too]]." The point was that she was trying for a role that was out of her skill set. In later episodes when singing "[[RunningGag Soft Kitty]]" to Sheldon, she has a passable singing voice.
* {{Hypocrite}}: Penny shows several signs of hypocrisy, often she will call others out on things she does or has done herself. For example she criticises Leonard for being so insecure about the relationship he would resort to interfering with her relationship with a male student she was working with, despite several episodes earlier interfering with Leonard's relationship with Sheldon's female assistant for exactly the same reason. She also tells Sheldon he can't tell Amy what they can't do, only for Sheldon to point out that she commonly tells Leonard what he can't do. Although the others do sometimes show shades of Hypocrisy, Penny's the only one where it is normally not played for a joke.
* TheILoveYouStigma: She's got some commitment issues. These are not entirely her fault -- it is implied and later explicitly stated that she once said "I love you" to someone too early, and that someone went on to treat her like crap. Finally says the L word to Leonard in Season 6 and the emotional gravity of the moment makes her cry.
* ImportantHaircut: During the 45 days between Season 7 and 8, her long locks have become a [[http://img2.wikia.nocookie.net/__cb20140912175519/bigbangtheory/images/1/13/NewPenny.png shorter pixie haircut]], that slightly resembles [[http://www2.pictures.stylebistro.com/gi/Jennifer+Lawrence+Short+Hairstyles+Messy+Cut+F7DYuKMVNr1l.jpg Jennifer Lawrence]] as part of a new adult look. Sheldon, of course, hates it.
* InSeriesNickname: Her father Wyatt called her "slugger". He stopped when Penny got her first training bra. It was difficult to keep pretending that Penny was his son.
* InstantExpert: If she is genuinely interested in playing a game, she tends to be almost a savant at it. She was better than Sheldon her first time playing ''Franchise/{{Halo}}'' and beat Leonard at Chess ''while'' he was teaching her how to play.
* IntimateMarks: She apparently has a Chinese character tattooed on her right buttock. It is either for "Courage" or "soup" depending on whether you believe her or Sheldon.
* TheLadette: While she can be very feminine and dressed-up sometimes, it's a running gag that she knows more about masculine activities than the guys. It's implied the guys started drinking more because of her (leading to the discovery of what it does to Raj), she was antsy about meeting a burglar so she could "go Nebraska on his ass" with a bat, loved going to the gun range with her dad, and when the guys needed someone who knew about manly things (specifically fishing) she was the one they turned to.
* LightFeminineAndDarkFeminine: The Dark to Bernadette's Light. Penny is the more seductive of the two, more sexually experienced, and has a more noticeable temper. Bernadette is less overtly flirtatious, has a more stable love life, and she is slower to anger. (Though Bernadette can be more intimidating as seen in [[TheBigBangTheory/SeasonEight Season 8]]). They are close friends.
%% * LikeBrotherAndSister: Towards Sheldon.
* LikeParentLikeSpouse: After psychoanalysing Penny, Leonard's mother tells him that if he wants to have sex with Penny he should use the same kind of cologne her father wears.
* LiterallyLovingThyNeighbor: Has a relationship with Leonard who lives across the hall in the same apartment building.
* LittleBlackDress: Seems to be a favorite of hers when going out for a night on the town.
* LovableAlphaBitch: Being a gorgeous young woman, it shows up every so often, mostly involving her relationship with Bernadette and Amy. In one episode, she realized she was a high school bully and was sorry about it.
* LoveInterest: For Leonard, thus providing much of the show's plot impetus.
* MamaBear: Messing with or hurting one of the boys is a very good way to get an angry Penny after you. [[spoiler:Just ask Lucy, or Alicia, or Todd Zarnecki.]]
* ManicPixieDreamGirl: In its own way, this is what Penny is to all of the guys. Leonard and his friends Sheldon, Howard and Raj are content with their lives of scientific research at Caltech and being concerned with any given upcoming nerdy activity such as Klingon Boggle. When Penny moves in next door she is neither a genius or a nerd, but is actually an average girl with a vibrant social life. Being around her Leonard can't help but see the contrast between her going out dancing and them sitting at home playing ''VideoGame/WorldOfWarcraft'' together. While it is most evident with Leonard as they become romantically involved with each other, everyone evolves significantly by having her in their lives.
** In a reversal, Penny never really gave much thought to the academic pursuits these guys are involved with on a daily basis. While she is hopelessly unable to keep up with their Technobabble, after some time she retains knowledge and is fascinated with a few thought experiments, famously Schrödinger's Cat in the first season finale. By the fourth season she has admitted that it is hard for her to keep less intelligent company around. By season six, she has gone back to school, taking a history class and, as of season seven, a psychology class.
* MasculineGirlFeminineBoy: Masculine Girl to Leonard's Feminine Boy. It's a product of her personality that she doesn't take any crap from people while Leonard will just suffer through humiliation to avoid conflict. In Season 6, Bernadette's father tries to take Howard fishing as a bonding exercise. Howard realizes he had better learn how to fish, and asks Raj and Leonard to help him figure out who he can ask to train him in Typical Guy Stuff. One GilliganCut later, they are knocking on Penny's door. It's also revealed that she rebuilt an entire tractor engine all by herself at the age of ''twelve''. It's also sometimes played with, as she certainly likes girly things and can be quite emotional at times, leading to this gem when she first tells Leonard that she loves him.
-->'''Leonard:''' "Are we just going to pretend this isn't a big deal?"\\
'''Penny:''' "...That's exactly what we are going to do, because... (tearing up) you're about to make me cry. And we both know if I start crying, ''you're'' going to start crying!"\\
'''Leonard:''' (tearing up as well) "Yeah, you'd better go."
* MasterOfTheMixedMessage: She treated Leonard almost like a brother in the first season, despite kissing him a few times in addition to some mild flirting. Yet, when he mustered the courage to ask her out in the finale, she seemed surprised that he was interested in her, and only then started to consider him as someone date-able. When they get back together in Season 5 and started their relationship beta-test, she would swing back and forth from a very casual JustFriends relationship to suggesting they make-out to pass the time when the power went out, which Leonard caught on and even joked about. Early Season 6, she confessed to Amy and Bernadette that she was worried about leading him on and was almost ready to break up to avoid hurting him again, only to be swayed by his PuppyDogEyes and they finally had sex again.
-->'''Penny:''' ''I didn't know what else to do. He had those big, sad eyes.''\\
'''Bernadette:''' ''[[SarcasmMode Yes, of course, you had no choice]]?''
* {{Meganekko}}: She once donned some glasses to help her [[SmartPeopleWearGlasses look smart]] and started saying random science terms like "molecules". The resultant look [[GeekyTurnOn drove Leonard crazy]].
* MoodSwinger: Part of the premise is that Penny is a very emotional girl who frequently baffles the guys with her illogical mood swings.
* MsFanservice: The first couple of seasons especially had her in short shorts and cleavage heavy tank tops as regular outfits. As evidence of her character growth and age (she was 21 in the first season), she started dressing more like an adult than a teenager, now more often wearing slacks and blouses. That said, she never really stopped dressing in such a way that shows she knows what she has, and how to use it. After Kaley Cuoco's real-life horse-riding accident, they stopped showing her legs to hide her surgical scars, which had no in-universe explanation.
* MustHaveCaffeine: In one notable instance, she came over to the guys' apartment, declared "out of coffe, need coffee" and poured herself a cup like it was nothing, pissing off Leonard's new girlfriend, who was unaware of her DropInCharacter status in the process.
* NerdNanny: She provides the page image. She lives across the hall and simply likes the company and Leonard. Although we do see why they hang out with each other, as the guys, most especially Leonard and Sheldon help her out with her problems when she's experiencing them and she helps them get a lot less bullied than they normally still are. Another difference is that they do do things without her coaxing, and she does hers without theirs, but usually in their own social circles and what they try to get from the other party is a crossing of boundaries.
* NotAMorningPerson: She has a rule for no one to knock on her door before 11:00 am or she will punch them in the throat.
--> '''Penny:''' It's six thirty in the morning! *slams door*\\
'''Leonard:''' Didn't you grow up on a farm?
* OddFriendship: Towards ''everyone''. Penny and Sheldon are VitriolicBestBuds. By Season 4, when Leonard gets a new girlfriend and Penny decides to keep her distance, she comments how she's missed being around to hear Sheldon's "jibber jabber". Similarly, she admits she considers even ''Howard'' a friend of hers by the end of Season 4, [[ContinuityNod even if she did once break his nose for him trying to stick his tongue down her throat).]]
* OfficialCouple: Penny and Leonard when they start dating.
* OldShame: In-universe example. In Season 7, she confides that early on after moving to LA she appeared topless in a shower scene in an ultra low-grade horror movie called ''Serial Ape-ist'' (with a KillerGorilla) that was never released. After telling Sheldon he lets her know that everyone already knew, Howard googled the movie almost the moment she left after meeting them for the first time. Could be FridgeBrilliance, she was so ashamed of the role that she was a little more picky about what she auditioned for and that's the reason she has next to no acting roles.
* OnlyOneName: Her last name is unknown to the audience, Bill Prady said it will be revealed eventually. Lampshaded on the Season 6 blooper reel, when Johnny ad-libbed a joke about Penny having issues by asking what her last name was and Kaley, caught off guard, exclaimed "I don't know!"
* OnlySaneWoman: Even saner than Leonard, especially when the guys are over complicating something or have dived too deeply into a fandom to realize they're not being normal.
* OvershadowedByAwesome: She can hold her own with her fiancee and their circle of friends but she is of average intelligence and isn't as educated.
* ParentalSubstitute: Sheldon often views Penny as a substitute for his mother (who is alive, just lives away from him in Texas); he wants her to take care of him when he's sick, or sing him a lullaby. This is especially emphasized in the episode "The Guitarist Amplification", when Sheldon runs away to the comic book store, because he can't bear Leonard and Penny fighting, and Penny makes it up to him by buying him a robot and a comic book.
* PopCulturalOsmosisFailure: By and large is ignorant of most of the geeky things such as who StanLee is, although she is more familiar with the music, reality shows, and romantic comedy scene than the guys (other than Raj).
* [[PrettyFreeloaders Pretty Freeloader]]: Penny is a relatively mild version of this. She doesn't live with the guys, but she eats their food whenever they get takeout (most nights) and uses their Wi-Fi since she refuses to pay for her own. This is lampshaded many times: Sheldon complains about it and frequently changes the wi-fi password ("Penny already eats our food; she can pay for Wi-Fi. No spaces."), only for Leonard to promptly inform her of the change. Sheldon even changes the Wi-Fi password to "Penny is a freeloader" and Penny accepts it without seeming to care. Howard and Raj wonder why Leonard allows her to do this, even when they're not dating.
* RaisedAsTheOppositeGender: Her father wanted a son so badly that he forced her to play all sorts of sports so he could pretend she was a boy.
* ReallyGetsAround: She opposes the idea that she sleeps around, despite Sheldon's ''math'' saying otherwise. She has mentioned sometimes grabbing the nearest guy for a weekend of sex after a breakup, but doesn't like doing it.
* SexForServices: In ''The Hook-Up Reverberation'', it is implied she provided this, to a degree, to a lesbian PE coach at high school in return for straight A's. All Penny would disclose is that "it worked out just fine", so this remains AmbiguouslyBi.
* ShiksaGoddess: Howard at one point calls Penny a Shiksa Goddess. She fits the stereotypical vision of the trope by being blonde, though she is green-eyed not blue-eyed.
--->''(to Raj)'': You're missing the point! A Shiksa goddess is not an actual goddess. We pray ''on'' them, not ''to'' them.
* ShipperOnDeck: She is "so digging the [[PortmanteauCoupleName The Shamy]]". Supporting the Sheldon/Amy relationship.
* SmartPeopleWearGlasses: Utilized by her in TheTag of "The Egg Salad Equivalency." In an effort to better understand Leonard she considered taking some science courses at the local community college, only to find that she just can't keep up with it. Instead she bought some glasses to make herself look smarter, which is good enough for Leonard.
-->'''Leonard''': Glasses? I really don't think that's gonna change *Penny puts them on* ''oh my God, you look so smart and hot!''
-->'''Penny''': I know, right? Watch this. *lowers glasses sexily* ''Molecules.''
-->(Leonard leads her towards his bedroom)
-->'''Penny''': Where are we going?
-->'''Leonard''': To my bedroom so I can take everything off but those glasses. And maybe the boots!
* TheSmurfettePrinciple: In the first three seasons, when she was the only female lead. Afterwards, Amy and Bernadette were added to the main cast.
* StreetSmart: She's StreetSmart but BookDumb whereas the rest of the characters are Book Smart but don't always have the best instincts in real world social settings.
* SuspiciouslySpecificDenial: With regards to finding out Leonard was hit on by Alex Jensen, a female grad student.
-->'''Penny:''' Should I be worried?\\
'''Leonard:''' What? No! Of course not. Why?\\
'''Penny:''' Because she's pretty and she's smart. And when you talk about work, she doesn't have to go home and look up words in the dictionary to understand what you said.\\
'''Leonard:''' You do that?\\
'''Penny:''' (quickly) No!
* TeamMom: Sometimes she plays the part for the boys alongside Bernadette. Sheldon often treats her as his mom because Mrs Cooper lives in Texas and she's across the hall.
* TomboyAndGirlyGirl: The Tomboy to Bernadette's Girly Girl. She is physically stronger and more athletic than Bernadette. Penny is more interested in football, while Bernadette loves to dress as a Franchise/DisneyPrincess.
* TomboyWithAGirlyStreak: Girly Girl with a Tomboy Streak. She's fairly feminine with her interests in fashion, shoes, nails and pursuing a career in acting, but she's very tough and knows more about traditional manly interests like football, hunting or fishing than the guys. See also GirlyBruiser and TheLadette.
* {{Trekkie}}: Penny is supposedly not into science fiction shows. But she picked up enough interest in ''Star Trek'' to see the [[Film/StarTrek 2009 film]] before any of the others.
* TrueLoveIsExceptional: Her "type" at the beginning of the series was the dimwitted, JerkJock type. The main romantic pairing of the series is her and Leonard; Leonard being the exact opposite of this.
* UnkemptBeauty: She isn't afraid of being seen "less than perfect", often lounging in sweats, an oversized t-shirt and hair messily pulled back. Although in an episode detailing her ''VideoGame/AgeOfConan'' addiction they do go out of their way to depict her as genuinely messed up and not this trope (with blotchy skin, greasy and frayed hair).
* UnresolvedSexualTension: Between her and Leonard. The main thrust of the show, nudge nudge, the "bang" in the Big Bang. Season 3 had them in a RelationshipUpgrade into the OfficialCouple, but they broke up before the end due to Penny having doubts about how committed she is to Leonard. After some time both characters had more or less moved on while remaining friends but the UST returned, and they explore being together as a couple again in the fifth season.
* ValleyGirl: Played this way near the beginning when set up as Leonard's love interest. Since then, her rather sordid Nebraska upbringing moved into a CoolBigSis mindset.
* VitriolicBestBuds: With Sheldon and Howard. They annoy her to no end but she cares for them.
* WaitingForABreak: Being an actress. In season 8, she has become a sales person representing a pharmaceutical company.
* WellDoneDaughterGirl: She does everything she can to make her dad proud, but it doesn't work because she's a girl.
* WellExcuseMePrincess: She loves Leonard, but isn't shy about calling him out on his shortcomings
* WhiteSheep: Well, compared to her sister, who shot her husband while drunk and her brother who cooks meth, Penny could be considered this.
* WillTheyOrWontThey: With Leonard, although his interest in her is admittedly much stronger. The show built upon the first two seasons of flirting and false starts just to get them officially together. They break up before the end of the season and don't get back together until mid way through the fifth season. They spend the next year or so trying to feel secure enough being together (Leonard's insecure about her attractiveness, Penny's insecure about his intelligence) and once they both come to grips with what they want out of their relationship they get engaged at the end of the seventh season. And even from there their engagement takes time.
* WomenAreWiser: Played with. Penny has a lot more real world experience than the guys, but is just as prone to making dumb mistakes or decisions.

[[folder:Howard Wolowitz]]
!!Howard Joel Wolowitz, M.Eng.
->'''Played by''' Simon Helberg
--> ''The way I see it, I'm halfway to pity sex.''

Of the four male leads, the only one without a doctorate (for which he gets made fun of a lot despite that he has a master's degree from [=MIT=] and is an aeronautical engineer). As no group of geeks is complete without a BasementDweller, he lives at home with his mother, despite being in his late 20's at the start of the show. In addition, he is Jewish and practices the faith but [[CulturalRebel enjoys not eating kosher from time to time.]] Also, among the group, he was a mixture of the CasanovaWannabe and ExtravertedNerd until he met and started dating Bernadette.
* AbhorrentAdmirer: To Penny, he behaved rather perverted until she gave him [[TheReasonYouSuckSpeech a verbal beatdown]].
* {{Adorkable}}: His song to Bernadette in the episode in the episode "The Romance Resonance" qualifies. He is singing what would his life be if he did not have her. He fills it with science and science fiction references in his usual nerdy style. Among the lines are: "I'd be Series/DoctorWho without the TARDIS", "[[Creator/SteveJobs Jobs]] without the Wozniak", "You're like uranium-235, and I'm uranium-238; Almost inseparable isotopes", "I'd be string theory without any string", "I'd be binary code without a one". "A cathode ray tube without an electron gun", "I'd be Series/{{Firefly}}, [[Series/BuffyTheVampireSlayer Buffy]] and [[Film/TheAvengers Avengers]] without Creator/JossWhedon", "I'd speak a lot more [[Characters/StarTrek Klingon]]" (immediately followed by a line in the Klingon language), and "We're like changing electric and magnetic fields; You can't have one without the other". The whole song is dorky, but adorable in revealing how much Howard values his wife.
* AllMenArePerverts: A classic example, at least in early seasons, the season 7 premiere even has Sheldon tell Penny that Howard looked up her nude scene online shortly after meeting her.
* BasementDweller: Finally removed in the sixth season when he marries and moves in with Bernadette. Long beforehand the show had gone to great lengths to give this trope some HiddenDepths, acknowledging the cultural tendency of Jewish children to live with their parents until marriage. Howard's father also left them when he was eleven, he was always hesitant to leave because he knew she would be left all alone without him.
* BerserkButton: He doesn't like being reminded that he doesn't have a [=PhD=]. Every time he tries to start something, Leonard tells him to sit down and he complies. He might not have a [=PhD=] but he recognises he's too puny to do anything about it.
* BetaCouple: With Bernadette. Likely implemented because of the irony that the pervy swinger ends up being the first of the group to get married.
* BookDumb: According to Sheldon, for being "just" an engineer and the only one without a Ph.D. As Howard points out, many engineers simply don't bother going for a Ph.D after getting their Masters, since they are ''already'' more than qualified for most of the jobs in their field.
* BrainyBrunette: He fills this role along with over half of the other characters, including Leonard, Sheldon, and Raj. He even once notes that (stereotypically) brunettes tend to be the smartest girls.
* BreakoutCharacter: While Sheldon was always among the primary trio (along with Leonard and Penny) and his popularity was apparent almost immediately, Howard has gradually been elevated into one of the more prominent cast members. The fifth season introduced two running plotlines for him, his upcoming marriage to Bernadette and being selected for a NASA mission. This is interesting because besides some evolving character dynamics the show had never really done such a StoryArc before.
* ButtMonkey: He's often made fun of by Sheldon and everyone else (sometimes, even [[HypocriticalHumor Penny]]) for his lack of a doctoral degree, his relationship with his mother and his CasanovaWannabe status. He was also the Butt Monkey to the other astronauts who constantly picked on him and bullied him when he was in space.
* CasanovaWannabe: His success with women is inversely proportional to the effort he puts into trying to get anywhere with them. Mainly because his idea of "effort" consists of skeevy pickup lines, pretending to be a goth, hookers, and generally being a creepy, sexist bastard. When he initially doesn't try hard with Bernadette, he finds himself doing much better, and eventually bonds with her by [[BeYourself being himself]], rather than trying to act out his inaccurate self-image.
* TheCastShowOff: Helberg is a [[http://www.youtube.com/watch?v=4YxlLzbzYiM brilliant impressionist]] and they've given him the opportunity to demonstrate it. Memorably, he does a StephenHawking impression in an episode where he later appeared AsHimself, with Helberg having to do the impression with Hawking on set watching him off camera. He's also not a bad singer, as he's shown a few times. Most notably his song for Bernadette in Season 7. He was also a stage magician and has performed magic tricks in a few episodes.
* CharacterDevelopment: After getting together with Bernadette, he's actually started to become nicer, more honest and less sleazy. He could still be a {{Jerkass}} from time to time, but he's still better than before. The few times his sleazy personality shows up (ie. ogling women at a gym), it only serves to remind you of how far he's come. This comes to a head in Season 5's "The Stag Convergence" where he openly admits to Bernadette he is disgusted with how he was before and that he changed because of her.
-->'''Penny:''' That was the most beautiful thing I've ever heard, and it came out of ''you!''
* ComicallyMissingThePoint: In "The Engagement Reaction" When Bernadette finds out the real reason why Howard's mother was in the hospital she chews him out for it. (He didn't know until she told her.) When she is asked where she is going she responds back with the following lines, everybody but Howard is surprised that she sounds like Mrs. Wolowitz when she shouts.
--> '''Howard:''' Where are you going sweetheart?
--> '''Bernadette:''' [Wolowitz voice.] TO THE TOILET!!!! IS THAT OK WITH YOU?!!
--> -everyone but Howard reacts in surprise.-
--> '''Howard:''' Is it me or does she sound sexy when she's angry?
* CulturalRebel: Enjoys not keeping Kosher. His favourite meal at the Cheesecake Factory is a bacon cheeseburger -- "breaking two Jewish dietary laws at the same time."
* CunningLinguist: Or so he thinks. In reality, he only knows enough of each language he claims to speak in order to hit on women unsuccessfully.
* DeadpanSnarker: Over the course of time, he [[CharacterDevelopment evolved]] into the second-biggest one among the group, after Penny. From the second biggest [[ButtMonkey snark-catcher]] (after Sheldon), no less.
* DisappearedDad: Howard's father left his wife and his son when Howard was 11.
* DudeWheresMyRespect: Is hit by this when he comes back to earth after getting into space. Most of his friends got sick of him talking about his trip in space.
* EmbarrassingNickname: Was dubbed "Fruit Loops" by the other NASA astronauts. Named after his favorite brand of cereals. The other astronauts overheard his mother mentioning his taste for the cereal.
* TheEngineer: His official status in the group. Howard has a master's degree in engineering from [=MIT=] and works for [=NASA=] as an aeronautical engineer, which eventually earns him a coveted spot on the next Soyuz rocket to the [=ISS=].
* EverythingsBetterWithPrincesses: When Bernadette greeted Howard as Literature/{{Cinderella}}, he stripped off his shirt and said in a deeper voice, "My lady." (And tried to mime riding a horse to her.)
* ExtravertedNerd: Howard actually knows he's a nerd, but chooses to ignore this and act like he's cool in the hopes that people (especially women) will be fooled. He fits this trope so well he could perfectly be the TropeCodifier for younger viewers.
* FirstKiss: Sheldon and Amy kiss for the first time in "The Locomotive Manipulation" (Season 7, episode 15). They both enjoy it.
* FourTemperamentEnsemble: The Sanguine. Typically friendly and cheerful, confident of his skills, a charmer at his best moments (though he started out as a creep), very talkative, and has a talent for comedy.
* TheFriendNobodyLikes: Leonard and Raj get along with him fine, but it's made very clear that he and Sheldon are not really friends, otherwise. Penny also disliked him immensely in the first few seasons, until he learned to show her some respect.
* FriendToAllChildren: Sort of. At least in contrast to his [[ChildHater wife]].
* GeekPhysiques: His small size and thin build are the source of many jokes for people who know him. Howard is 5 feet, 4 inches (1.63 m) tall, and weighs 118 pounds (53.52 kilos).
* HandsomeLech: How he sees himself, although really he's a CasanovaWannabe.
* HenpeckedHusband: To Bernadette. [[spoiler:He bonds with his father-in-law over the fact both are this.]]
* HeterosexualLifePartners: He and Raj are close. Many a joke on the show is about how they are perhaps too close and perhaps not so heterosexually...
* HiddenDepths: He was at least somewhat aware of how women viewed him but felt that if he didn't try so hard he would never have a shot otherwise. In a Season 5 episode, he admits he's always wanted children, showing behind the sleazy flirting he's always wanted to settle down and raise a family. He is almost always the one to display a talent that would be put to use, such as sign language.
* HollywoodNerd: Played with, he dresses in severely outdated clothes and an unflattering bowl haircut, yet is proud of his small and skinny build.
* HomoeroticSubtext: With Raj, Dr. Beverly even stated they behaved like a committed couple.
* HouseHusband: After coming to terms with the fact that Bernadette isn't good with kids, he reluctantly agrees to be this once they decide to raise a family.
* InSeriesNickname: Bernadette calls him "Howie".
* InsistentTerminology: He does ''not'' live with his mother -- she lives with him.
* {{Irony}}: The biggest sleaze and perv of the group is the first to settle down. Despite not having a [=PhD=], he has probably done the most in terms of accomplishments.
* JerkWithAHeartOfGold: While this becomes a more apparent factor of his character as the series progresses , there have been indications even from earlier episodes. He clearly possesses an ostensibly sensitive nature, there are severe implications that his flirtatious nature was based on a desire for genuine companionship (lampshaded to an extent when he enters a relationship with Bernadette). He undeniably possesses some degree of compassion and genuinely cares for his friends, most of his undesirable characteristics are associated with his overly confident and sexually frustrated nature (which are almost completely non existent when he and Bernadette officially enter a relationship).
* JewishAndNerdy: He's a Jew and frequently makes self-deprecating comments about it. He works for NASA and holds a degree in space engineering. Like his friends, he's a lot into sci-fi, comic books, video games, robots, and other geeky stuff.
* KissingCousins: He lost his virginity to his second cousin Jeanie, when he was 15-years-old.
* LikeParentLikeSpouse: Howard thinks it's hot when Bernadette yells at him and sounds ''exactly'' like his mother.
* LimitedWardrobe: He ''always'' wears a turtleneck, which Amy later suggests might be connected to the fact he was circumcized. He also typically wears fairly tight clothing, unique belt buckles and an alien lapel pin (that apparently has some meaning but will never be revealed to the world).
* LovableSexManiac: He was obsessed with sex and women, making him a rather sympathetic sleaze. He calms down a bit when he gets into a long-term relationship with Bernadette.
* ManChild: He's very dependent on his mother to take care of many of his basic needs. When he (briefly) moves in with Bernadette, he sees nothing wrong with expecting her to cook his meals and do his shopping and laundry for him.
* MommasBoy: Oh, god, yes. While he makes jokes about his mother's weight, voice, and even makes quips about her dying, he nonetheless becomes very angry when Raj lampshades it, saying, "Don't you bring my mother into this!" There's also the fact he ''lets'' her treat him like a child half the time. Eventually [[FreudianExcuse explained]] that this developed from his father leaving them... he stayed her little boy so she could focus on loving him instead of feeling alone and worthless.
* NiceJewishBoy: At the beginning of the series, NiceGuy was probably the last thing you'd use to describe him. Though by the end of the second season, he had learned at least some manners, he was still way too oversexed. With the introduction of Bernadette, he's become a NiceGuy. Granted, he can get angry, but he's at least not dropping {{DoubleEntendre}}s in every single one of his lines.
* OnlySaneEmployee: When forced to babysit Sheldon, unlike [[TheCaretaker Leonard]] or [[TheQuietOne Raj]] who are resigned to attempting to appease him, Howard rarely cuts Sheldon any slack or puts up with his crap for very long.
--> '''Howard:''' Well, my power is the ability to pretend like I give a ''damn'' about your piddly-ass problem.
* OvershadowedByAwesome:
** PlayedForLaughs, despite having the most tangible affect on world progress than his friends (major engineering projects with NASA) and having a Masters degree from MIT, his lack of a doctorate is a frequent RunningGag.
** Averted in Season 5 when he fully shines. Even ''Sheldon'' is impressed that Howard is going into space. Well, impressed but certainly not more respectful, since in season 7 he outright tells Howard: "Truth be told, as a child, I did dream of going to space. Those astronauts were my heroes. And when you got to go, it was hard for me. [[BrutalHonesty Because it made me realize they’ll just send anyone up there."]]
* ProudToBeAGeek: Like Raj, while aware of the social awkwardness it can cause, he seems quite content with their geekiness.
* TheReasonYouSuckSpeech: He was unabashedly sleazy around Penny until she tore into him mid-Season 2, which devastated him until Leonard coerced her to apologize. While a joke was made he didn't learn his lesson, it is notable that he was no longer behaving like that around Penny afterwards.
* SensitiveGuyAndManlyMan: Manly Man to Raj's Sensitive Guy. His interpretation of manly is more just being unabashedly sleazy.
* SicklyNeuroticGeek: He is asthmatic, allergic to peanuts, almonds, and walnuts, prone to canker sores and pink eye, succumbs to seasickness, has an incredibly high genetic risk of heart illness, and has transient idiopathic arrhythmia.
* SmallNameBigEgo: With regards to his skills with women. Howard thinks he is a pickup artist, while his advances tend to creep them out
* ThatManIsDead: Regarding his sleazy persona.
* TheRuntAtTheEnd: [[ButtMonkey Much is made of the fact]] that he's the only one of the guys (and the only one of the group besides Penny) who doesn't have a Ph.D.
* TheyDo: With Bernadette. They married in the episode "The Countdown Reflection", season finale of 5.
* TookALevelInKindness: Used to be a humongous sleazebag. While he still retains some of these tendencies, he's grown out of it a lot, which he attributes to Bernadette.
* {{Trekkie}}: ''Star Trek'' is one of the group's favourite franchises. They especially dig ''Series/StarTrekTheOriginalSeries'' and ''Series/StarTrekTheNextGeneration'. When they went to a con once, he was dressed up as a Borg drone from ''TNG''.
* TwoDecadesBehind: His outfits are over the top, always very bright and colourful. For example in "The Lizard-Spock Expansion", Howard wears "a shiny blue rayon turtleneck, an obnoxious belt buckle with a golden crown inside a shield, a black and gold studded belt; pointy gold slip on shoes; and black leather pants." His outfits would be more in place in the [[TheEighties 1980s]] and [[TheNineties 1990s]].
* UglyGuyHotWife: Downplayed, they've simply acknowledged that there is an attractiveness gap between him and Bernadette. In addition, we actually see the courtship in full so we can see how well they match up in intelligence and sense of humor.
* VitriolicBestBuds: Mostly with Sheldon and Penny.
* VoiceForTheVoiceless: Raj often whispers what he intends to say and Howard interprets for him. Sometimes he says nothing or something completely else for laughs.
* YourCheatingHeart: In "The Hot Troll Deviation" (Season 4, episode 4), Bernadette catches him playing ''VideoGame/WorldOfWarcraft'' and having cybersex with Glisinda the Troll. This is treated as actual cheating and results in a temporary break up.

[[folder:Raj Koothrappali]]
!!Rajesh Ramayan "Raj" Koothrappali, Ph.D.
->'''Played by''' Kunal Nayyar
-->Excuse me! I have selective mutism, a recognized medical disorder. You're just a douche.

The TokenMinority, Raj is from New Delhi working in America on a visa as an astrophysicist. He is so shy around women, he is incapable of talking in their presence (even if not speaking to them, he can't talk if they are a part of the social group), eventually identified as Selective Mutism. The most consistent method of overcoming this is through alcohol, but he has tried several anti-anxiety medications with varying results.
* {{Adorkable}}: Many women find him "a cutie-pie" and if any of the guys is to succeed in one of their from-time-to-time escapade for wooing girls, it's usually Raj.
* AloneAmongTheCouples: He's the one in the group without a girlfriend for much of the time. Lampshaded frequently in Season 5 and 6. He sometimes acts like a jerk because of it.
* AmbiguousDisorder: Rather interestingly, Leonard's mom eventually diagnosed him as having "selective mutism." A good deal of his stories involve him trying to get around or push through his psychological issues, which hinder him a lot more than Howard's overcompensation or Leonard's low self-esteem.
* AmbiguouslyBi: He is the go-to guy for the HomoeroticSubtext, but even then the only guys he exhibits that behavior around tend to [[HeterosexualLifePartners be close friends he feels comfortable around]]. Most of the time he recognizes that something he says [[ThatCameOutWrong came out sounding weird or effeminate]], but other times he is completely unaware of the InnocentInnuendo. By and large it's clear he is attracted to women (why else would he clam up in their presence?) it's just filtered through his personality quirks "[[ItMakesSenseInContext Dance number aside, I'm SO not gay]]."
--> '''Raj (to Howard)''': Last night, I had a dream, we got so rich from the app we made, you and I bought matching side by side mansions. [[DoesThisRemindYouOfAnything But, there was a secret tunnel connecting your front yard to my back yard.]] [[FreudWasRight What do you think it means?]]\\
'''Howard''': It means next time we play handball, I'm showering at home.\\
(''While playing TabletopGame/DungeonsAndDragons'') "The first ogre I see, I'm gonna run up behind him, whip out my wand, and blast my magic all over his ass!"
* BerserkButton: More Hysteric Button, but he collapses in panic when anything threatens his residency status and the prospect of having to return to India looms.
* BitchInSheepsClothing: Howard points out that it's his inability to talk around women that keeps his less pleasant traits hidden in some contexts.
* BollywoodNerd: He's Indian, nerdy, and the TokenMinority of the group.
* ButtMonkey / TheChewToy: His inability to speak around women occasionally makes him this, as he has to whisper his comments to Howard, who pretends he said something completely different.
* CampStraight: He fits many of the CampGay stereotypes but is attracted to women. According to Raj: dance number aside, he is definitely not gay.
* CannotTalkToWomen: When sober. [[spoiler:Now completely cured ever since Lucy broke up with him.]]
* CharacterDevelopment: Despite his selective mutism being almost his primary character trait, he is ''slowly'' working through it. One issue brought up in Season 6 was that despite his handicap he was rather superficial when it came to women "I want them to love me for me... but they have to be super-hot, like a 9 or a 10." He then met Lucy, a mousy, timid girl with a lot of social anxiety and they bond over their struggles. [[spoiler: When she dumps him for pushing her too hard to meet his friends, he is shaken up enough to talk to Penny sober, finally cured of his mutism]].
* {{Cloudcuckoolander}}: He definitely has his moments of this.
-->'''Raj:''' [completely out of nowhere] I'm thinking about adopting some sort of quirky affectation like a pipe or a monocle or a handlebar mustache.\\
'''Leonard:''' Why, for all the girls out there looking for the Indian [[TabletopGame/{{Monopoly}} Monopoly Man]]?\\
'''Raj:''' This is not a safe place. You can't share anything here.
* CulturalRebel: Raj hates India and everything to do with it, including and especially Indian food. He dreads talking to his parents for this reason, knowing they're going to try to guilt him into returning there.
* TheCutie: See {{Adorkable}}. He's also a CuteMute and ShrinkingViolet when he's around women.
* EverythingIsRacist: Interpretes many comments as racist and insulting to his Indian identity.
-->"Did you have to make me sound like a ''[[WesternAnimation/TheSimpsons Simpsons]]'' character!"
** You kind of have to agree with him about the cell phone voice recognition software.
--->'''Leonard:''' Let me try one! Calling Mcflono Mcfloonyloo!
--->'''Cell phone:''' Calling... Rajesh Koothrappali.
--->'''Rajesh:''' Impressive! ...and a little racist.
** After Howard imitates the Bollywood Breakdance routine that Raj performed whilst heavily inebriated the night before:
---> '''Raj''': That's very offensive.
---> '''Howard''': Yeah, we thought so too.
** This even applies when the potential racism isn't aimed at Indians:
--->'''Raj''': Spiders give me the jeebie jeebies.
--->'''Howard''': It’s heebie jeebies.
--->'''Raj''': I know, but that sounds anti-Semitic.
* ForeignPeopleAreSexy: More cute than actually sexy...but Raj still tries to milk ''this'' for all its worth.
* {{Flanderization}}: He started off just as nerdy as the rest, his primary quirk being so shy he couldn't speak in front of women and a few jokes around him being a FunnyForeigner. His shyness and the HomoeroticSubtext in his relationships with the guys (since he rarely talks to women) eventually grew into him being AmbiguouslyGay with a lot of InnocentInnuendo and very rarely is there not a joke about him being the TokenMinority.
* FormerlyFat: Subverted. In "The Mommy Observation", Raj narrates a sob story about being fat as a child. "I was 200 pounds (90,72 kilos) by the time I was in middle school. Kids were mean. Cows may be sacred there, but it doesn’t help if you look like one." Leonard then reveals that Raj is lying. He has seen pictures of Raj in his school years and knows his friend was never a fat kid. Raj then admits it, saying "No, I was svelte as a gazelle."
* FourTemperamentEnsemble: The Melancholic. He is the group's sensitive guy. He is also moody, goes through periods of depression, is insecure about his chances with women, and bashful to a fault.
* FridgeLogic: He tends to start these kinds of discussion InUniverse, regarding the guys' various comic book, sci-fi, and fantasy fandoms.
* FriendlessBackground: Ambiguous use. In "The Mommy Observation", Raj narrates a sob story about being fat and lonely as a child, entertaining himself through inventing his own stories and games. Promising to himself that if he ever gets any friends, he will play these games with them. The story was supposed to elicit sympathy and guilt his friends to play murder mystery dinner with him. The fat part is immediately revealed to be a lie, but it is left unclear if he really was lonely in his younger years.
* FunnyForeigner: This trope is even name-dropped by Sheldon when describing everyone's respective roles.
* HandsomeLech: When drunk.
* HeterosexualLifePartners: With Howard.
* HiddenDepths: He has some talent in make-ups and party-planning. You want metrosexual stuff, go to him.
* HollywoodNerd: His awkward mannerisms and outfits (oversized, mismatching clothes) seem to impair his ability to score with women. He is otherwise handsome.
* HomoeroticSubtext: With Howard, [[AccidentalKiss they actually kiss once, not intentionally]], though. He and Howard also indirectly kiss when they're testing some internet software... He is also enticed by Leonard's demonstration of confidence and as of Season 6, he's been getting these moments with Stuart.
* InnocentlyInsensitive: At times, especially with Janine Davis after her husband left.
* InSeriesNickname: "Raj" is his nickname and is used more often than his actual first name.
* InTouchWithHisFeminineSide: He's a self-labeled '[[TheDandy Metro-sexual]]' and has most of his family and friends thinking he's gay. The fact that he's more feminine than the show's female characters doesn't help.
* InVinoVeritas: Can only talk to girls if drunk or medicated [[spoiler: until the Season 6 finale when he finally is able to speak to Penny, Bernadette, and Amy while sober.]] He has no problems talking to his mom or sister, though, thankfully.
* JerkJustifications: In later seasons, he seems to be more bitter about being the only one of his friends still single.
* LimitedWardrobe: Almost always wears a sweater-vest and switches off between a tan and blue jacket.
* LovableNerd: Like Leonard, though he becomes less lovable in later seasons.
* NiceGuy: More so in the beginning. See TookALevelInJerkass.
* NonIdleRich: Raj's family apparently is very wealthy, but he still chooses to have a career. According to Sheldon, they are halfway between [[Franchise/{{Batman}} Bruce Wayne]] and [[Characters/DisneyDucksComicUniverse Scrooge McDuck]].
* OutOfFocus: He never completely disappears from the show but among the primary cast in the later seasons, he typically gets a couple of ADayInTheLimelight episodes and not a whole lot else to do in between. This is more noticeable after Amy and Bernadette became more prominent, as they ended up taking time away from his interactions with Sheldon and Howard.
* ProudToBeAGeek: Like Howard, while aware of the social awkwardness it can cause, he seems quite content with their geekiness.
* PungeonMaster: Most of the {{Incredibly Lame Pun}}s come from him.
* QueerPeopleAreFunny: Most of the gay jokes of the show comes from Raj.
* TheQuietOne: His inability to talk to girls while sober aside, he is decidedly the one of the foursome who talks less - in many scenes, his participation consists basically of throwing a snarky comment here and there.
* SensitiveGuyAndManlyMan: Sensitive Guy to Howard's Manly Man.
* ShrinkingViolet: Around women.
* ThatCameOutWrong: Raj is pretty much the poster boy for this.
--> ''Oh, great! The first monster I see, I'm gonna sneak in behind him, whip out my wand, and blast my magic all over his ass!''
* ThrowTheDogABone: In the earlier seasons, if any of the guys were going to get lucky when at a party, it would end up being him, [[{{Irony}} the guy with the most trouble talking to girls]]. In the later seasons, as the others have become more successful, he has slowly spiraled into depression over how much more pronounced his issues are. Still, every so often he does manage to get a girlfriend for a brief time and in the sixth season he meets Lucy, who sticks around longer than most.
* ThrowingOffTheDisability: After a rather heartbreaking experience in Season 6, [[spoiler: Raj can finally talk to women without being drunk.]]
* TokenMinority: He is the only Indian guy in the group, and the only one not white. He actually likes to play this up, hoping his exotic looks give him an edge.
* TookALevelInJerkass: Has started going down this direction. At the beginning of the series, he was actually one of the nicest ones in the group. But as of Season 4, [[spoiler: has advocated for Howard and Bernadette to break up so he could get with her, to the point where he has a dream about Howard dying and him getting with Bernadette, and instead of congratulating them upon their engagement, cries to himself . Then he supposedly sleeps with Penny. In Season 5 premiere, he is unapologetic about any of it, even keeping it a secret that he and Penny did not actually have sex.]] Howard did say that Raj is always obnoxious, but his inability to speak to women when sober prevents others from experiencing his jerk-ass tendencies as much. This is highlighted in the Season 7 opener, where [[spoiler: after being cured of his mutism]] he still has problems with saying the completely wrong thing.
* TotallyRadical: Tends to add "Dude" at the end of/beginning of sentences.
* {{Trekkie}}: Like his friends, he's a ''Star Trek'' fan.
* TheVoiceless: Whenever a woman is around.
* WalkingSpoiler: [[spoiler: He was cured of his mutism in the finale of the sixth season, after a break-up with Lucy shocks him out of it. SIX full seasons of holding to the "can't talk to women without alcohol" quirk, a lot of episodes gave him a beer in hand just to get through an episode. Now, in the seventh season and beyond, his problems are slightly more normal but may be confusing to anyone who didn't catch the few episodes explaining his "rehabilitation."]]
* WhamEpisode: The Season 6 finale. [[spoiler: Lucy dumps him and Penny goes to console him, discovering he is now cured of his mutism]].
-->'''Penny:''' [[spoiler:That's the booze talking.]]\\
'''Raj:''' [[spoiler:No, it's not! [[WhamLine I haven't had a drink since last night]].]]\\

[[folder:Amy Farrah Fowler]]
!!Amy Farrah Fowler, Ph.D.
->'''Played by''' Mayim Bialik
-->Aw, it's the alcohol and drug peer pressure my mother warned me about, I was beginning to think it was never going to happen. Yes please!

Sheldon's {{nerd}}y DistaffCounterpart, the group found her during a dating site prank they pulled on Sheldon. She grows attached to Penny and becomes both her best friend and {{Foil}}. As a result she formed a distaff relationship compared to Sheldon and Leonard. While she mirrored Sheldon in almost every aspect initially, over time she branched out through both her friendship with Penny and feeling a romantic attraction to Sheldon.
* AbhorrentAdmirer: Not so in looks, but in behavior. She starts off as a subversion of this trope (only wanting to fake a relationship with Sheldon to placate her concerned Mother) but then going on to make unwanted advances at both Sheldon and Penny. PlayedForLaughs, naturally.
* {{Adorkable}}: When Stuart expressed an interest in Amy, his reasons for it was that she didn't look upon him "with ball-shriveling contempt." Basically saying that she was cute and not intimidating.
* AllWomenAreLustful: In clear contrast to the largely-asexual Sheldon.
* AmbiguousDisorder: Even more so than Sheldon at times, although she is more outgoing.
* AmbiguouslyBi: Though her interest in males has developed a bit since her initial appearance, she's ''very'' appreciative of Penny and fawns over her more than any other character seen in the show thus far. She's made a few sparse comments of the same type about Bernadette as well. For an example she gave Penny a ''very'' large painting of the two of them, and told her that it originally had the two of them ''nude'' but she had it changed as she didn't want it to "challenge their heterosexuality".
** An alternative to this is more of a perpetual StupidSexyFlanders, she's straight but openly appreciates the attractiveness of her own gender.
** One time, Amy mentions Penny has a better chance of getting with her than Leonard does.
* AttentionWhore: ... would hardly begin to describe her.
-->"Today is not about you! Today is about Howard and Bernadette and [[ItsAllAboutMe me]]!"
* BetaCouple: With Sheldon.
* BiTheWay: Amy is attracted to both Sheldon and Penny, although her crush on Penny is PlayedForLaughs due to how awkward her flirting tactics are.
* TheBore: Initially an even worse case than Sheldon was, considering she has none of the same interests in entertainment as any of the group. After CharacterDevelopment, she makes an effort to be less boring.
* BrainyBrunette: She's a Neurobiologist, after all.
* BrokenBird: Unlike Sheldon, who is implied by family members to have always been as he is, there's hints that Amy had a very lonely and troubled childhood that resulted in her current character.
* BrutalHonesty: Amy is a firm practitioner of this.
* ButIWouldReallyEnjoyIt: Frequently invokes this whenever she tries to convince Sheldon to turn their relationship physical.
* CatchPhrase: "Hi, bestie" to Penny.
* CelebrityParadox: In an episode before her introduction, Raj referred to "that girl from ''Series/{{Blossom}}'' being really smart." Evidently Amy and her actor Mayim Bialik co-exist here.
* CharacterDevelopment: She actually gets more development than any other character (except maybe Howard). When Amy was first introduced, she was emotionally repressed, TheStoic and basically a female Sheldon. Since she's become friends with Penny and Bernadette she's opened up socially and has become a far more friendly person who, unlike Sheldon, makes genuine efforts to get along with other people. Despite her improvements, in late season 4 and season 5 (and to a lesser extent, season 6), Amy often comes off as blunt, desperate, eccentric, and even creepy (her pseudo-lesbian comments about Penny), and her desire to be normal and accepted sometimes made her an AttentionWhore. However in the last few seasons (especially 7) her weirdness and annoying traits have become almost completely non existent, she's now one of the most normal characters on the show, ''much'' CloserToEarth than Sheldon (who is still the weirdo of the group), well aware of her boyfriend's quirks, but still endlessly patient and willing to put up with him.
* CharacterizationMarchesOn: Two-fold. Her first few episodes she was almost [[DistaffCounterpart an exact, if female, copy of Sheldon]], complete with having similar character tics and vocabulary. She eventually grew to be some combination of ExtrovertedNerd ''and'' ShrinkingViolet, one who was ecstatic to be friends with Penny, [[AllGuysWantCheerleaders a cheerleader type]]. It's been explained as rapid character growth because of her friendship with Penny, but still causes a strange contrast with her earlier portrayal. In a second example, throughout Season 4 and nearly every episode of Season 5 she would make some sort of [[QueerPeopleAreFunny flirtatious remark in Penny's direction]], with Penny switching off between being flattered and disturbed. It hasn't shown up since the start of Season 6.
* ChastityCouple: With Sheldon, much to her dismay. Inititally they agreed there would be no physical relationship, but over time Amy developed into wanting one. While Sheldon has no interest in it (and doesn't recognise certain behavior, like helping her bathe and rubbing [=VapoRub=] on her chest is arousing to her) he has admitted to her and others that she influenced him and ''he'' considers theirs a deeply intimate relationship even if they aren't physical.
* CloserToEarth: While she's Sheldon's intellectual equal, she gloats less (though she's just as blunt), is more aware of social norms, and actually has some desire to be normal. She also doesn't seem to have any geeky interests like Sheldon. Except the harp. And, in Season 4, she connected Penny to an EEG while she cries.
* CovertPervert: Though she doesn't actually make any attempt to actually hide it, it's still pretty surprising whenever she not-so-subtly talks about her masturbatory habits.
* DistaffCounterpart: Began as one to Sheldon, but her friendship with Penny and Bernadette has lead to...
* DivergentCharacterEvolution: Was originally a female Sheldon, but grew out of it.
* FirstKiss: Sheldon and Amy kiss for the first time in "The Locomotive Manipulation" (Season 7, episode 15). They both enjoy it.
* FormerTeenRebel: Sort of inverted. She was not actually this when she was a teenager but clearly wants to be this in the present. Whenever one of the others take her along on legally dubious activities (like repainting Sheldon's parking spot) she seems to get a thrill over it.
* FourTemperamentEnsemble: There are only three women in the ensemble, but she is the Phlegmatic. She is incredibly patient and accommodating in her dealings with Sheldon, a good listener, and rather shy and insecure.
* FriendlessBackground: She has a preoccupation with friendship activities, especially with Penny, because this is the first time in her life she's been able to experience anything of the sort.
* TheFriendNobodyLikes: She was this at first in her trio with Penny and Bernadette, it becomes a plot point in one episode when Amy gets upset because the girls go shopping without her. She seems to mostly grow out of it as the three of them become better friends, and Amy even grew closer to Bernadette (even though she considers Penny her best friend). In one of the later episodes we actually find her and Bernadette ditching Penny and hanging out together so they can have more intellectual conversations.
* GenericCuteness: Averted. While Amy is by no means "ugly", she definitely looks unusual in comparison to Penny, Bernadette, Sheldon's twin sister, or even Priya (Raj's sister). Mayim Bialik brings this up about herself in [[http://www.youtube.com/watch?v=zmC0tsVnfQM this interview]] about "geek girls" with Kari Byron of ''Series/{{MythBusters}}''.
* GiveGeeksAChance: An extremely RareFemaleExample.
* HarpOfFemininity: She is seen owning one and often plays it for recreation or when she's sad.
* IJustWantToHaveFriends: She craves companionship and friends because she was very lonely in her childhood, teenage years and young adulthood until she met Sheldon and his social group. She's willing to do many things to make Penny, a cheerleader type, her particular friend.
* ImprobableAimingSkills: Amy demonstrates this in "The Weekend Vortex", explaining that she spent a ''lot'' of time throwing coins into wishing wells during her childhood, hoping for friends.
--> '''Amy''': At a certain point, you start doing trick shots just to keep things interesting.
* InnocentlyInsensitive: Told Bernadette during wedding dress shopping that she's beautiful but still not as beautiful as Penny.
* InSeriesNickname: In "The Locomotive Manipulation", Sheldon suggests several pet names for her. They are all rather insulting. [[Characters/TheLordOfTheRings Gollum]], "Flaky", "Princess Corncob", and "[[Characters/TheAddamsFamily Fester]]". Amy finds all of them unacceptable.
** In "The Spoiler Alert Segmentation", Penny calls her "Ames".
* InsufferableGenius: In the early seasons, she was a toned-down version of Sheldon, and thus wouldn't hesitate to tell you the brutal details of how the universe or neurobiology worked. As of the sixth season, though, her insufferability has nearly vanished, especially in her almost... ''normal'' boyfriend-girlfriend complaints with Sheldon.
* IntelligenceEqualsIsolation: Unlike Sheldon, she went unwillingly through this; hence, her craving for social interactions in general, especially with other women.
* ItsAllAboutMe: Shows tendencies at times. Her speech at Howard and Bernadette's wedding:
--->'''Amy''': Bernadette, I want to thank you for allowing me to be your maid of honour. I also want you to know, that I will be happy to do it again if this marriage craps out.
--->'''Leonard''': [[DeadpanSnarker Thank you, Amy. Very touching.]]
* JerkWithAHeartOfGold: She genuinely doesn't seem to realize how rude she can be (especially to Penny), but when she thinks Penny's depressed she rushes to cheer her up. Or she's thrilled about being a bridesmaid in Howard and Bernadette's wedding. When they decide to get married at the courthouse before he gets into space, she wears her bridesmaid dress and tiara, and angrily stops the others from fighting.
* LastEpisodeNewCharacter: In Season 3. Notable in that it was a very brief appearance and all we knew of her was her name and the fact she was almost identical to Sheldon. Nothing was known of whether she was a scientist like the others, and by the following season Mayim expressed amusement that they matched their degrees.
* LimitedWardrobe: Although her sense of fashion has changed extensively via contact with Penny, she is typically seen in very old-fashioned sweaters and skirts, once admitting her entire outfit once belonged to her grandmother.
* {{Meganekko}}: Mostly beacuse SmartPeopleWearGlasses.
* MotherNatureFatherScience: She forms a classic scientific duo with Sheldon with her in Biology (nature) and Sheldon in Physics (hard science).
* NoSocialSkills: Zigzagged. Amy has no natural social skills, but as a neurobiologist, she is fascinated with societal behavior, and knows about a lot of them. However, it's all book knowledge, and she's both poor at application, and there are rather big holes in her knowledge.
* PromotionToOpeningTitles: In Season 4.
* PunnyName: Her name is a play on "Fair or Foul" but has never been called out inverse.
* QueerPeopleAreFunny: She's the go-to girl for when the gay jokes turn lesbian, in Season 5 she would make a remark towards Penny OnceAnEpisode. This was almost eliminated outright in Season 6. However it made a resurgence in Season 8.
* SheCleansUpNicely: She typically wears rather dowdy clothing with a long skirt and shapeless sweaters (along with Mayim Bialik's self-described "ethnic" looks), but in part due to Penny's influence she sometimes manages to dress up for special occasions and catch others off-guard with how well she turns out. Fans also noticed how attractive she became in the [[Series/StarTrekTheOriginalSeries Nurse Chapel]] costume while [[https://www.youtube.com/watch?v=HNsqHtzxY1o "Playing Doctor" with Sheldon]] ''Franchise/StarTrek''-style. She also wasn't bad looking as [[https://www.youtube.com/watch?v=QDdrnacKumg Snow White either when the girls hit Disneyland]].
* SixthRanger: She join the group in Season 4 and becomes part of the regular cast.
* SmartPeopleWearGlasses: Like Bernadette and Leonard she wears glasses. She is also highly intelligent.
* TheStoic: At first. She gets better after awhile.
* TooKinkyToTorture: at one point she gets sick, and Sheldon is induced to come take care of her. She enjoys his solicitous behavior so much that she [[FawltyTowersPlot starts faking her illness]] to keep him around. Once he finds out, he decides that his only recourse is to take her over his knee and spank her. She can barely hide her glee.
* TVGenius: Being a DistaffCounterpart to Sheldon (more evident in her early appearances).
* [[ManChild Woman Child]]: Amy shows on several occasions a level of immaturity, quite like her boyfriend. However unlike most examples, she's closer to a teenager than a child. She treats her friendship with Penny and Bernadette as if she's in the cool girl click at high school, has a very teenage attitude towards sex and relationships, tries on several occasions to act cool (as in like a teenager from the [[TheNineties 1990s]]) and reacts to attention other girls don't want positively. A lot of this stems from simple isolation, and never having the experience she dreamed of when she was a teenager.

[[folder:Bernadette Rostenkowski]]
!!Bernadette Mary-Anne Rostenkowski[[spoiler:-Wolowitz]], Ph.D.
->'''Played by''' Melissa Rauch
-->I remember the first time I looked through a microscope and saw millions of tiny micro-organisms. It was like a whole other universe. And if I wanted to I could wipe it out with my thumb like a god!

Howard's miniature-sized romantic interest. A microbiologist, she is often [[CloserToEarth the voice of reason and by far the gentlest character of the show]]. In a contrast to the other scientists of the show, she doesn't have much difficulty in navigating a successful social life. Despite being sweet and bubbly, she can and ''has'' gotten angry enough to scare the others. She started out as a friend of Penny who also worked at the Cheesecake Factory to pay for her schooling, she later graduated with her doctorate and is working a very lucrative job for a pharmaceutical company.
* {{Adorkable}}: Petite and cute with a squeaky voice and a love for "Disney/{{Cinderella}}".
* AffablyEvil: She's the nicest person on the show. She also invents things that are made for biological warfare.
* BadLiar: Never, ever get Bernadette to lie. It will go very badly indeed. For tropes involved see: SuspiciouslySpecificDenial, HurricaneOfExcuses, ActingUnnatural, and InventionPretension indeed.
* BetaCouple: With Howard. Their relationship is actually a bit more of a roller coaster than most examples, as they had broken up for some six months between the third and fourth seasons and every other episode of the fifth season was introducing a new relationship hurdle they had to get through. Although them getting through the tough parts showed how good they are for each other, leading up to their marriage.
* BerserkButton: Though not quite as insane as Sheldon, she is a walking panel of tiny berserk buttons. Don't try and dress as Literature/{{Cinderella}} when she called it. She's also shown to be extremely competitive during scavenger hunts.
* BewareTheNiceOnes: Despite being possibly the nicest character on the show, she has a real temper when angry. Her line of work is also ''extremely'' morally sketchy -- she makes bioweapons for God's sake! Her vicious side comes out in full in "The Parking Lot Escalation" with an argument between Howard and Sheldon spilling over between her and Amy. She will go from demure to outright venomous in a second.
-->"''I'm the one who had your car towed!''"
* BuxomIsBetter: She is fairly well endowed, and this was mentioned in the show.
-->'''Howard's Mom:''' (regarding a custom made vest) She has a tricky figure, she's short and ''stacked'' like me!
* CharacterizationMarchesOn:
** One of her defining traits in her introductory episode is that she didn't really get any of the jokes the others would share, and behaved a little bit like Sheldon. Her second episode was similar (In response to Howard seriously proposing to her "Is this one of those jokes I don't understand?"). In her third episode she admitted to laughing just because it made Howard smile, while still not getting them (though she would try to [[DontExplainTheJoke explain some jokes]] to the others). Since then it's never reappeared.
** Mid-Season 4, her personality started to evolve to what she is best known for, a [[BewareTheNiceOnes sweetheart with an undeniable vicious side]]. A Season 7 episode lampshades it, after a minor subplot with her mistaking a "Get Well Soon" card for a co-worker in the hospital for a Retirement card ("Good luck with wherever you end up"), she expresses some relief that the co-worker is in no shape to actually read it. Howard, bemused, asks if she was like that before they got married.
* TheChick: More so than Penny.
* ChildHater: It stems back to when she was forced to take care of her younger siblings because her mother worked full time. This caused problems for Howard, who always dreamed of becoming a father.
* CloserToEarth: Compared to pretty much everyone (even Penny).
* CompetitionFreak: During Raj's scavenger hunt, she is ''merciless'', berating Leonard for moving slowly (despite the fact that he has asthma and running quickly could potentially trigger an asthma attack), and was willing to run over pedestrians so that she could win.
* ContraltoOfDanger: Bernadette usually has an adorably squeaky voice... until she gets pissed off. Then her voice drops low and the other characters know she means business.
* CovertPervert: Don't let her cuteness fool you. She is not above putting on schoolgirl and Franchise/DisneyPrincess outfits to turn on Howard.
* CuteButCacophonic: When she gets angry she yells alot, at which can match [[NoIndoorVoice Howard's mother]].
* CutenessProximity: Loses it with recreating prom and when it comes to Disneyland and dressing as Literature/{{Cinderella}}.
* TheCutie: She's cute, small, sweet and her high-pitched voice is {{Adorkable}}.
* DaddysGirl: Her father appears to have a soft spot for her, calling her his "little girl".
* DatingWhatDaddyHates: Played with, her father barely hides his contempt for Howard as a person but has expressed some admiration for Howard's accomplishments.
* DumbBlonde: Completely subverted. She may talk in a cutesy voice and play {{the ingenue}} around Howard, but she's also a microbiologist with an interest in physics as well (she's every bit Howard's intellectual equal). She mentions at one point that she puts on this facade to make Howard feel more secure in his own intelligence.
* FourTemperamentEnsemble: There are only three women in the ensemble, but she is the Sanguine. Typically friendly and cheerful, compassionate when her friends have problems, forgiving of Howard's flaws and indiscretions, and personally charming.
* FunSize: Bernadette is the sweetest, cutest member of the gang. At 4' 11" (1.50 m), she's also the shortest. She needs a stepping stool just to see through her peephole.
-->'''Bernadette''': I've never seen you wear this dress, it's adorable!
-->'''Penny''': That's because on me, it's a shirt.
* HeelRealization: In an interesting subversion of TheUnfairSex, she was unsettled when Howard announced his chance to go to outer space because he didn't discuss it with her first. Howard apologized and tried to backtrack with a formal couple discussion on the matter, and she flatly stated he wasn't going and dragged ''his mother'' into the argument. It was only after talking with Amy and Penny did she realize that she was in the wrong. Quoth Amy, "We're not here to judge. We're just here to be supportive until you realize what a despicable thing you've done."
* HeightAngst: Like Leonard, she is annoyed by how short she is (4'10"-5'0"). She sometimes blames her Mother for smoking during her pregnancy with her and laments she's too short for most amusement park rides and some grade school children are taller than her.
* HiddenDepths: Normally, polite, sweet and kind. This does not translate to being soft or a pushover. When the girls cosplay as princesses, however, her demeanor changes... "I'm driving the car, it was my idea, I'm gonna be Cinderella. You bitches got a problem with that, we can stop the car right now!"
* HotScientist: In-universe, she has been picked as one of the fifty most beautiful female scientists in California for an article in a magazine.
* HugeGuyTinyGirl: Not with Howard, who is only a few inches taller, but with an old boyfriend Glenn, played by 6'7" (2.01 m), former basketball player Rick Fox.
* TheIngenue: She's rather oblivious to Howard's double entendres at first.
* InSeriesNickname: Her former college professor and boyfriend Glenn calls her "Bernie". Howard heard the nickname from Glee, and took up using it.
* LimitedWardrobe: She typically likes flower-print skirts and button-up sweaters.
* LightFeminineAndDarkFeminine: The Light to Penny's Dark. Penny is the more seductive of the two, more sexually experienced, and has a more noticeable temper. Bernadette is less overtly flirtatious, has a more stable love life, and she is slower to anger. (Though Bernadette can be more intimidating as seen in [[TheBigBangTheory/SeasonEight Season 8]]). They are close friends.
* MadScientist: Some of [[NoodleIncident her]] [[TheVirus work]] in microbiology seems to veer into this territory, if she ''[[SuspiciouslySpecificDenial wasn't]]'' joking!
* MagicalGirlfriend: Howard seems to see her as one. He actually was a geeky loser, and terribly unlucky at love before meeting her. Then she entered his life. She is beautiful, sweet, and devoted to him. Although she is not extraordinary, other than her MadScientist tendencies.
* {{Meganekko}}: A petite blonde microbiologist who always wears glasses.
* MsFanservice: She wears normal clothes to work, but in later seasons she wears a lot of fanservicey clothes at home.
* MyBelovedSmother: Although her mother never appears onscreen (until 'The Fish Guts Displacement'), this is one of the things she first bonds with Howard over. Her mother calls her at work every day to see if Bernadette had a healthy lunch. She also lays out Bernadette's clothing for her every morning. And they don't even live in the same house.
* NoodleIncident:
** She and her fellow microbiologists [[FunnyAneurysmMoment apparently crossed the Ebola virus with the common cold]]. [[SuspiciouslySpecificDenial Not that they'd ever admit it.]] "That would be a terrible, terrible thing!"
** In another incident:
--->'''Bernadette''': So Amy, what are you gonna be working on at Cal Tech?
--->'''Amy''': I'm leading a study to see if deficiency of the monoamine oxidase enzyme leads to paralyzing fear in monkeys.
--->'''Bernadette''': Well, if they're anything like humans, the answer's yes.
--->'''Amy''': Wait, you've...you've done this experiment on humans?
--->'''Bernadette''': [[SuspiciouslySpecificDenial You mean like death row inmates with nothing to lose? No, that would be unethical.]]
* ObfuscatingStupidity: She admits to doing this around Howard at times.
* OlderThanTheyLook: Bernadette is in her thirties and she still get's mistaken for a child. One kid even calling her a "mean kid with big boobies".
* OverlyLongName: After her marriage, she is, officially, Bernadette Marianne Rostenkowski-Wolowitz. Penny jokes that she should claim the website of that name before someone else does, only for Bernadette to reveal that Howard already has.
* ParentingTheHusband: To Howard, who is still a ManChild MommasBoy.
--->'''Bernadette''': Why are you being a baby?
--->'''Howard''': I’m not a baby. I’m a grown man, and I made the bed. Now where’s my star?
* PerpetualSmiler: Bernadette is ''always'' smiling. And it's the always same smile, (see her picture above) whether she's enjoying time with her friends or saying some incredibly creepy and threatening things. Seriously, she wears the ''same damn smile'' when offhandedly commenting on her lab crossing Ebola with the common cold. And denying having done so a second later. Not to mention the conversation she has with Howard about how to talk to her father.
* PromotionToOpeningTitles: In Season 4.
* PutOnABus: In "The Plimpton Stimulation". Offscreen, no less.
** TheBusCameBack: She returned in "The Hot Troll Deviation" [[spoiler:and got back together with Howard.]]
* RaisedCatholic: One reason she and Howard bond is because of their shared rebellion against their religious traditions.
%% * SarcasmBlind[=/=]CaptainObvious
* ShiksaGoddess: The Shiksa Goddess to Howard. She fits the type by being blonde and blue-eyed. They initially connect over freaking out their families. Bernadette, being Catholic, is thrilled at the prospect of freaking out ''her'' parents. Their relationship has since moved beyond that joke.
%% * SickeninglySweethearts: Was portrayed this way with Howard, up until the 8th season where they started snapping at each other more regularly.
%% This is stilll zero-context.
* SilkHidingSteel: Despite her height, her apparent meekness and her mannerly behavior, she's among the rare characters able to make Sheldon shut up and abide. She can even handle Howard's mother, which is ''NO'' easy feat.
* SixthRanger: Is introduced in Season 3, and joins the main cast in Season 4.
* SmartPeopleWearGlasses: She's got a Ph.D in microbiology and wears glasses.
* SmarterThanYouLook: People tend to forget she is a microbiologist due to her personality. She once said she either wanted to be a microbiologist, physicist, or an ice dancer.
* SweaterGirl: Wears formfitting cardigan sweaters as part of her regular wardrobe.
* TeacherStudentRomance: She dated one of her college professors, Glenn, for a year.
* TeamMom: She and Penny take turns on this. She can even handle Sheldon.
* TheyDo: With Howard. They married in the episode "The Countdown Reflection", season finale of 5.
* TomboyAndGirlyGirl: Girly Girl to Penny's Tomboy. Bernadette loves to dress as a Franchise/DisneyPrincess, dresses in florals and skirts, and gets excited about her prom-do over. She makes Penny look butch.
* TookALevelInJerkass: Seems to get more and more pronounced each season. Most of this is belittling Howard. Season 8 especially. Penny only nabs the sales rep Job because the hiring manager was too afraid of her to say No to Penny. A later episode revealed she once called said hiring manager's 7 year old grandson a wuss at a company picnic. Another episode of said season paint her as the mean girl of the group.
* {{Tsundere}}: Type B. She's usually a sweetheart, but when she gets angry...
* UglyGuyHotWife: Let's face it. Bernadette is ''way'' out of Howard's league, who is also a perverted creepy loser in addition to being far less attractive than sweet, beautiful Bernadette. Often lampshaded by Penny that wonder WhatDoesSheSeeInHim.
* VocalEvolution: Bernadette's voice was always pitched higher than [[http://www.youtube.com/watch?v=TUO39s8aMos Melissa Rauch's natural voice]]. Her [[http://www.youtube.com/watch?feature=player_detailpage&v=dvD8NvkgE4I#t=73s initial voice]] is much less "squeaky" than her [[http://www.youtube.com/watch?v=7aqlGSTcYp4 later voice]] (although that also varies depending on the episode).
* WhatTheHellHero: To Raj when Leonard reveals to Howard that Raj used to have a thing for her. Of course, she also calls him a "Cutie Pie" after she's done chewing him out.

!Family Members
[[folder:Mary Cooper]]
!!Mary Cooper
->'''Played by''' Laurie Metcalf
->"Leonard, the Lord never gives us more than we can handle. Thankfully, He blessed me with two other children who are dumb as soup."

Sheldon's mother, she's a religious fanatic who, despite their differences, is very close to Sheldon emotionally. She is generally warm and friendly and with a southern charm that draws everyone else to love her immensely. Although not book-smart, she is extremely wise. In a comparison to Beverly Hofstader, she is essentially the mother Leonard wished he had.

* BrutalHonesty: Not the same as Sheldon, but very blunt all in all. This seems to run in Sheldon's family.
* CastingGag: Like Sara Gilbert and Johnny Galecki, another ''Series/{{Roseanne}}'' alum.
* FormerTeenRebel: Penny refers to her as a Born-Again Christian, seemingly backed up by Mary's comments that when she was younger, [[ReallyGetsAround she'd put out]] for a car ride and a bottle of strawberry wine.
* TheFundamentalist: Is a strict Christian, nevertheless, she's still a Cool Mom.
* GoodParents: Again, a contrast to Beverly Hofstadter.
* HollywoodOld: Defied. Her age is never mentioned but she looks like she gracefully aged into her mid 50's.
* InnocentBigot: Will often say unintentionally racist comments, is frequently lampshaded.
* InnocentlyInsensitive: For one example, she mentions her minister could try to perform an exorcism on Raj to rid him of "foreign devils" that inhibit his ability to talk to women.
* MoralityPet: For Sheldon. He may be a jerk in lots of situations, but he sure loves his mommy.
* ParentalSubstitute: She tends to be this for Leonard; for all that she tends to be TheFundamentalist and is [[BookDumb not particularly well-educated]], she is nonetheless a [[CloserToEarth much more loving and sympathetic figure]] than Leonard's own mother, who treats Leonard as an errant test subject.
* PuritySue: [[invoked]] Has a few traits of this, largely in that everyone loves her. She has a bit of "righteous condemnation" attitude but admitted to Penny that at her age any guy could have her with a car and a bottle of strawberry wine.
* StreetSmart: She's a lot like Penny. She doesn't have a lot of book smarts, but she knows how to deal with the real world.
* TeamMom: She often plays mom to the entire troupe when she shows up and is especially fond of cooking large family-style meals for them.
* ViewersAreGeniuses: The embedded joke. Her name is Mary. She fondly calls her unworldly son ''Shelley''. Sheldon can be a monster sometimes; at all times he has difficulty making sense of the world. ''[[Creator/MaryShelley Mary Wollstonecraft Shelley]]'' wrote a novel about the creation of an UrExample monster. Mary Cooper gave birth to "Shelley"... her own Literature/{{Frankenstein}} creation.
* WomenAreWiser: Out of all the cast she's undoubtedly among the most sensible, mature and down to earth.
* YouAreACreditToYourRace: She makes blindly racist jokes that are [[InnocentBigot not really meant]] in an offensive manner, since she's just an old-school conservative.

[[folder:Beverly Hofstadter]]
!!Beverly Hofstadter
->'''Played by''' Christine Baranski
-->Excuse me Leonard, '''I am''' the one getting a divorce, Mitsy is the one who is dead, why are '''you''' the one making a fuss?

Leonard's mother, she's emotionally distant and entirely cold to him and has been his entire life, but those same qualities lets her find a kinship in Sheldon. She has a double specialty of Neurobiology and Psychiatry, specifically that [[TheCobblersChildrenHaveNoShoes of childhood development]]. In a comparison to Mary Cooper, she is basically the mother Sheldon wished he had.
* AbusiveMom: Made worse by the fact that whatever damage was done was seemingly unintentional. Some of her dialogue suggests that some of it ''may'' have been intentional, testing various theories on Leonard, his brother, and his sister. She used most of Leonard's childhood as the subject for at least two of her books, ''Needy Baby, Greedy Baby'' and ''The Disappointing Child''.
* AllPsychologyIsFreudian: Played with. Despite being a trained psychiatrist and acknowledging that Freud's theories are outdated, she still invokes this to manipulate Penny to the point of tears.
* AmazinglyEmbarrassingParents: She published a paper on Leonard's father and her sex life, complete with powerpoint presentation.
* BlondesAreEvil: Well, not really ''evil'' but as close as you can get. Her emotional torture of Leonard is horrible.
* CallingYourBathroomBreaks: Without even a hint of shame, at that. Almost her CatchPhrase:
--> '''Beverly:''' I have to urinate.
* TheComicallySerious: She's so serious about humorous or mundane topics that it's hilarious.
* CovertPervert: Alcohol brings it out.
* DefrostingIceQueen: She never shows warmth or nurturance of any sort towards anyone, coldly deconstructs anyone she talks to and virtually never thaws. However, she does loosen up a bit around Sheldon, [[StrangeMindsThinkAlike simply because they have so much in common.]] She loosens up a bit around Penny when she gives her some tequila. "Leonard, why didn't you tell me you've been tapping my homegirl?" In her second appearance she's slightly less formal and offers to help Leonard with his relationship problems...of course, she then dismisses Leonard's concerns with a "Buck up, Sissy Pants." but it's the thought that counts.
* DistaffCounterpart: To Sheldon, before Amy was introduced. Ironically, she serves as a {{Foil}} to Amy in this way -- while Amy has developed into a more "normal" character, Beverly needs alcohol before even a hint of human emotion begins to seep through, making her an extreme counterpart to Sheldon's eccentricities while Amy is a counterpart to his more caring and human side.
* [[EmotionlessGirl Emotionless Woman]]: Shows very little emotion at the best of times.
* HardOnSoftScience: According to her, she and her husband (an anthropologist) wrote a paper on the same subject (that they deliberately had sex only for procreation). Hers was "the only one worth reading, of course".
* InnocentInnuendo: Once had a memorable conversation with Sheldon that initially came across to the audience as the two of them contemplating having sexual intercourse... only for it to be revealed that they were actually talking about a ''karaoke duet''.
* {{Jerkass}}: She's incredibly cold and impersonal, and not only psychologically rips apart anyone she meets, but seems to enjoy doing it so she can analyze them, and regularly talks down to people. Leonard's anecdotes about her are almost universally about how cold and unloving she was and how much she favored his brother and sister over him. The only hints of ''normalcy'' in her come up when she's drunk, but most of the time she never shows the faintest hint of [[JerkWithAHeartOfGold a good person hiding beneath it all]].
* KarmaHoudini: Like Sheldon, her condescension and parental abuse are PlayedForLaughs, though unlike Sheldon she never seems to suffer even minor consequences for it.
* KubrickStare: Whenever she is about to indulge in some psychiatry, she looks over her glasses and gives an evil smile.
* LackOfEmpathy: For a good example, take note of the quote.
** Another example is her incredibly blunt manner when informing Leonard that his Uncle Floyd, the only family member he got on with, had recently died. Made far worse since it's entirely possible he could have been one of her siblings.
--->'''Leonard''': Oh my god, what happened?!\\
'''Beverley''': [[LiteralMinded His heart stopped beating]].
* MindRape: The resident mistress of this. For reference: She meets Penny for the very first time on the first floor of Penny's apartment, and after asking what Beverly does, they're on the third floor. By the time they get to Leonard's apartment (fourth floor), she has reduced Penny to tears.
* RunningGag: She likes to give people cat scans.
* ParentalSubstitute: Sheldon sees her this way, as the two of them have much more in common with each other than with Leonard.
* PsychoPsychologist: It's doubtful that her interest in her field was to help others. Mostly, she seems to treat everyone as lab rats.
* ShipperOnDeck: She apparently ships [[HomoeroticSubtext Howard/Raj]].
* SlasherSmile: If she smiles at you, run. If it is coupled with her KubrickStare, run faster. She is about to destroy your childhood memories.
* WhyAreYouNotMySon: For all the concern her son shows to her, she couldn't care less. Most notable is when she thanks Sheldon for driving her back to the airport even though it's Leonard who's in the driver's seat.

[[folder:Debbie Wolowitz]]
!!Debbie Wolowitz
->'''Voiced by''' Carol Ann Susi


Howard's overbearing mother whom he insists lives with ''him'', rather than he with her. During the show, she has never actually been seen on screen, only [[TheVoice yelling from off it]]. According to Howard, she is very large in figure and sports facial hair. Has a tendency to treat Howard as if he is still a child, which he is often annoyed by and simultaneously enjoys on some level, and she also requires (or at least likes to have) Howard to help her with necessary tasks in daily life such as shopping and transport to/from fitness class and beauty clinics.

Sadly, her actress died in November of 2014 and TheCharacterDiedWithHer.
* AmazinglyEmbarrassingParent: To the point you can't help but feel ''genuinely'' bad for Howard! She treats him like a little kid and is too much to take.
* CallingYourBathroomBreaks: She is incredibly... well, open about being in the bathroom, and sometimes even the details of it. Especially with Howard.
* DCupDistress : She has a "tricky figure" and compares herself to Bernadette.
--> She's short and stacked, like me.
--> Not like you, Ma, she never steps on hers!
* IWasQuiteALooker: Once said so in Season 6, when she went buying some clothes with Sheldon, going as far as stating she shouldn't eat all the chocolates her suitors gave her.
* JewishMother: Brooklyn accent, gives Howard a hard time about not becoming a doctor, cooks a lot of delicious food, demanded Howard marry a Jewish girl, nags, guilts, etc.
* JewsLoveToArgue: Half of her lines are regarding some disagreement with Howard. He, of course, pays it right back.
* MyBelovedSmother: She's overbearing and cares too much, regarding her son is an adult. [[TheUnseen If she was seen at any point,]] she'd be the page image, no doubt. There is the fact that half the time, Howard not only lets her, but seems to enjoy it to an extent. Like begging her to make him lamb stew or give him cherry popsicles.
* NoIndoorVoice: Whenever heard, she is almost ''always'' yelling. Usually justified since she's usually heard calling to Howard from the bottom of the stairs. While he's on the International Space-Station, Howard jokes that that she doesn't need to yell down the phone, because he can hear her even in ''space!''
* NoNameGiven: For most of the show's run her first name has been unknown. [[spoiler:It's finally revealed as Debbie at the end of Season 7.]]
* PassedInTheirSleep: Dies at Howard's Aunt Gladys while she was sleeping.
* SheWhoMustNotBeSeen: Although in "The Spoiler Alert Segmentation" she can be briefly seen in the background from behind as she shuffles around the kitchen. (It is unknown if the figure in red sitting alone on the roof in the wedding episode is Debbie Wolowitz or not)
* ShoutOut: To Maris Crane of ''Series/{{Frasier}}'' fame.
* SupremeChef: Zigzagged. According to Leonard, her brisket just melts in the mouth. However, her Thanksgiving specialty "tur-briske-fil" (turkey stuffed with brisket stuffed with gefilte fish) has to be swallowed like pills. When her freezer lost power and they had to finish off the last of her food lest it spoil, they state that the food was delicious, but it gave them all heartburn.
* TeamMom: Serves this role when Mary Cooper isn't around. She comforts, feeds, and smothers the gang (like Raj) and when she died, the gang remembered that she was a kind person that opened her heart and home to them and treated them like family.
---> '''Leonard:''' To Mrs. Wolowitz, a loving mother...to all of us.
* TheVoice: She makes a blink-and-you'll-miss-it appearance in UnrevealAngle in Season 6, though they don't show her face.
* YiddishAsASecondLanguage: Her speech is peppered with Yiddish terms. "YOU KNOW I CAN'T TURN ON THAT ''VERKAKTE'' COMPUTER!!!"

[[folder:Dr. V. M. and Mrs. Koothrappali]]
!!Dr. V. M. Koothrappali and Mrs. Koothrappali
->'''Played by''' Brian George and Alice Amter
-->'''Mrs. Koothrappali:''' Rajesh, are you letting your sister date that little Howard boy?
-->'''Dr. Koothrappali:''' Now, hold on. If she is dating an American, that's not a bad way to go. He's Jewish. Those chaps are very successful, and they don't drink a lot.

Raj's parents who live in India, they hope their son will settle down with a nice (Indian) girl someday and are very willing to set him up with people. They never appear in-person but instead talk to Raj and Priya via video-chat.
* ADayInTheLimelight: Both characters appear for only a few minutes per episode, speaking via video-chat. Dr. V. M. Koothrappali had a more substantial role in "The Clean Room Infiltration" (Season 8, episode 11), where he visits his son. He appears in the B plot, interacting with Penny and Amy.
* AmazinglyEmbarrassingParents: They are ''constantly'' trying to set Raj up with a nice (Indian) girl, and they have no problem using a formerly overweight girl's low self-esteem to their son's marital advantage. And they verbally wonder if Sheldon and Leonard are a gay couple as well. Right in front of them.
* ArrangedMarriage: Despite believing in this tradition, they actually married for love.
--> '''Dr. Koothrappali''': And it's been ''[[BlatantLies wonderful]]''...
* CloserToEarth: Raj's father, but only slightly.
* DeadpanSnarker: Both of them can slip into this.
* GentlemanSnarker: "We are very rich in a very poor country, so, all in all, can't complain."
* GermansLoveDavidHasselhoff: Invoked, as ''Series/DoogieHowserMD'' is apparently their favourite show;
--> '''Mrs. Koothrappali''': Grandma, wake up, it's Doogie-time!
* MeddlingParents: That they are able to do so from the other side of the planet is amazing.
* OpenMindedParent: Often suspect that Raj might be calling to give them the "gay talk" and show acceptance to the idea, despite Raj repeatedly protesting that he's ''[[CampStraight straight]]'', albeit somewhat [[TheDandy metrosexual]].
* ParentalFavoritism: Somewhat towards Priya. How they are with their other four children is unknown, but Raj's comments make them sound like very loving parents overall.
* PhraseCatcher: Raj's father has one associated with him, whenever Raj claims to have grown up poor;
--> ''"Your father's a gynaecologist. He drives a Bentley!"''
* YouGotSpunk: Dr. Koothrappali is quite impressed when Penny states that they'd be lucky to have her as a daughter-in-law.

[[folder:Missy Cooper]]
!!Missy Cooper
->'''Played by''' Courtney Henggeler
->"You listen to me. If you wanna start acting like a brother who cares about me, then terrific. Bring it on. But you try one time to tell me who I should be sleeping with, and you and I are gonna go round and round the way we did when we were little. ''Remember''?"

Sheldon's fraternal twin sister and his polar opposite. Despite this, [[SoProudOfYou she is actually very proud of him, and claims that she never stops bragging at home about how her brother is a]] "[[ITakeOffenseToThatLastOne rocket scientist]]." She immediately attracts the attention of the other three guys, but the only one she seems remotely interested in is Raj.
* AwLookTheyReallyDoLoveEachOther: Though they don't have much in common, and Sheldon's tendencies often lead to arguments, they're still siblings, and they do love each other.
* BrutalHonesty: One of the only qualities she shares with her fraternal twin. When Leonard asks her out...
-->'''Missy:''' Aw, that's so sweet! But no thanks.\\
'''Leonard:''' ...Oh. You have other plans...?\\
'''Missy:''' No.
* DeadpanSnarker: This appears to be Missy's preferred method of dealing with her brother and flirtatious suitors. When asked by Leonard, Howard, and Raj about how she knows Sheldon (they don't know she's his sister yet), her response is:
-->"Oh, he once spent nine months with my legs wrapped around his head."
* FakeShemp: She re-appears in Season 7, giving birth to her first baby. However, considering the whole of the arc is about Sheldon's reaction to becoming an uncle, and she's only ever heard-off screen or seen with her face obscured, it's unlikely that the studio had been able to get the original actress back.
* GroinAttack: Her preferred way of dealing with Sheldon.
* InformedFlaw: Her mother, Mary, says her two children other than Sheldon are "dumb as soup." Missy, while not as intelligent as Sheldon, doesn't seem to be ''dumb'' by any stretch of the imagination.
* KickingAssInAllHerFinery: She [[GroinAttack takes care of]] Sheldon while wearing a dress and heels.
* MsFanservice: Compared to Sheldon, she definitely knows how attractive she is and wears nice dresses and heels during her brief appearances.
* OneShotCharacter: She's only appeared once in the series so far, although there have been several other mentions of her by Sheldon and their mother. Sheldon's more likely to talk about Missy than their older brother, George.
* PolarOppositeTwins: With Sheldon. Sheldon is wildly egocentric, only interacts with others when forced to and tends to look down on anyone who isn't as smart as he perceives himself to be. Missy is out-going, friendly, level-headed and sociable.
* SiblingYinYang: Aside from their similar physical features, they are literally polar opposites in personality and behavior. However, Sheldon is excited by the prospect that Missy may carry the genes to produce another "him", or Sheldon 2.0.
* SoProudOfYou: Probably one of the sweetest moments between Sheldon and any of his family is when Missy prepares to leave and tells Sheldon that she's always bragging to anyone who'll listen about her brother "the rocket scientist". Of course, Sheldon takes offense to being called anything except a [[InsistentTerminology theoretical physicist]], but it's the overall thought that counts and it shows that Missy is very proud of her brother's academic accomplishments.
* SouthernBelle: She wears nice clothes, speaks with a thick Southern accent, and behaves in a much more mature and mellow manner than her brother.
* StatuesqueStunner: Like her twin brother, Missy towers over Penny and the other three guys.

[[folder:Priya Koothrappali]]
!!Priya Koothrappali
->'''Played by''' Aarti Mann
-->''I have five brothers and sisters. One of them is bound to screw up real big and'' then ''I'll tell my parents about you.''

Raj's sister and Leonard's love interest for a good part of Season 4.
* AlwaysSomeoneBetter: Penny sees her this way (with some prodding from Amy), in regards to her career and education level.
* BitchInSheepsClothing: She's not a bad person, but not as nice as she's fond of acting like.
* BrainyBrunette: She's a lawyer who graduated at the top of her class at Cambridge.
* CulturalRebel: A little. She apparently, according to Sheldon, "enjoyed the sweet taste of Hindu rebellion in the form of a Bob's Big Mac cheeseburger". She also doesn't have much problem dating Leonard against her parents' wishes and directly against her brother's orders (which the Hindu Code of Manu explicitly forbids).
* DatingWhatDaddyHates: Her parents wanted her to date an Indian.
* ForeignPeopleAreSexy: According to Amy, anyway. Leonard seems to feel the same, and even wanted to try out positions in the Kama Sutra with her.
* IWantMyBelovedToBeFashionable: Made Leonard dress cooler/ditch his trade mark hoody and insisted he [[TheGlassesGottaGo get contacts]]. This was actually treated as a ''bad'' thing because minor changes in his wardobe led to her making bigger demands like pushing Penny out of their social group (nevermind that there are three other people including her ''brother'' who are friends with her in said group).
* LongDistanceRelationship: She and Leonard tried. It didn't work.
* RememberTheNewGuy: She is introduced in this way.
* RomanticFalseLead: Pretty much a textbook case.
* RulesLawyer: Literally in one episode, where she picks apart the roommate agreement which Sheldon has written and allows Leonard to exploit every loophole in it.
* YourCheatingHeart: After coming back to India, still in a relationship with Leonard, she cheats on him with her ex-boyfriend. In the following episode it's implied that she and Leonard have broken up.

[[folder:Mike Rostenkowski]]
!!Mike Rostenkowski
->'''Played by''' Casey Sander
-->''Of course. A pretty girl like Bernadette, she'll find a new guy.''

Bernadette's father and later Howard's father-in-law, a retired cop and a man of few words.
* BerserkButton: Make that several buttons, according to Bernadette: In order, JimmyCarter, gardeners, foreign people, homosexuals, Sean Penn, the Second Vatican Council, gun control, organic food, the designated hitter rule, recycling, and his daughter marrying a Jew.
* DeathGlare: He really, ''really'' seems to enjoy giving these to Howard.
* HenpeckedHusband: He may be a retired cop, but that doesn't mean his wife can't make him do things.
* HeteronormativeCrusader: Implied: "homosexuals" are in the list of things he doesn't like.
* {{Hypocrite}}: Bernadette's description of him implies he is a very conservative Catholic (he disagrees with Vatican II... which happened in 1965.) but he later encourages her to get a pre-nuptial agreement [[note]] Catholicism isn't against prenups per se, but in case the spouse dies and to set out how to divide property, [[http://en.wikipedia.org/wiki/Prenuptial_agreement#Catholicism divorce isn't approved of]][[/note]].
* JerkWithAHeartOfGold: He's usually rude and unsympathetic towards Howard, but genuinely loves his daughter.
* NotSoDifferent: Both he and Howard get pushed around by their wives to spend time with each other, which they ironically bond over.
* ObnoxiousInLaws: Played with, he barely hides his contempt for Howard as a person, but has expressed some admiration for Howard's accomplishments.
* RetiredBadass: We knew he was a retired cop, but his [[EstablishingCharacterMoment introductory scene]] had him cracking walnuts with one hand. His primary characteristic is just how intimidating he is.

->'''Played by''' Keith Carradine
-->''I want grandkids before I die and I want them to grow up in a house without wheels.''

Penny's father.
* AmazinglyEmbarrassingParents: He is quite open about Penny's past boyfriends and her activities when she was younger, much to her chagrin.
* BeCarefulWhatYouWishFor: It's stated several times that Wyatt wanted his youngest daughter to be a boy, which messed with Penny's head when she was growing up. However, it's later revealed that Penny's brother came along a few years later, but her statements about him being a methhead and fleeing for the Mexican border doesn't make her father's granted wish oh-so great anymore.
* DatingWhatDaddyHates: He's [[GenreSavvy aware of this trope]] and tries yelling at Leonard to make him more appealing to Penny.
* DownOnTheFarm: He has a very similar mid-west "down to earth" personality to Penny.
* OnlyOneName: Like Penny, his last name hasn't been revealed.
* OverprotectiveDad: Subverted, he liked Leonard just from what Penny told him and long before meeting in person. After learning they broke up and [[TheBeard put on a deception]], he puts on a show of being the mean parent and instead quietly begged Leonard to figure out a way to make it work.
* PapaWolf: In "The Hesitation Ramification", Penny got a small part in an ''Series/NCIS'' episode. After it was cut, there's a scene with her talking to Wyatt on the phone, assuring Wyatt that no, he doesn't need to fly down and kick Mark Harmon's ass.
* ShipperOnDeck: For Penny and Leonard.
* WhyCouldntYouBeDifferent: He wanted Penny to be a boy. And then Wyatt finally got his coveted son a few years later, but considering how Penny describes her brother as a "kinda chemist" and asks God to make him stop cooking meth, it's likely that [[BeCarefulWhatYouWishFor this didn't go the way]] Wyatt planned, either.

!Secondary Characters

[[folder:Stuart Bloom]]
!!Stuart Bloom
->'''Played by''' Kevin Sussman
-->"Okay, if you are going to question the importance of [[RobertDowneyJr an actor's]] signature on a plastic helmet from [[Film/IronMan a movie]] based on [[IronMan a comic book]] then ''our lives'' have no meaning!"

The owner of the comic book store [[LocalHangout the guys frequent]], he is one of the few geeky individuals on the show who is otherwise not a supergenius like the others.
* AmbiguouslyBi: In Season 6, Stuart has apparently been without a date for so long that after an awkward moment with Raj, who later asks him if he wants to hang out sometime, Stuart comments to himself that he ''could'' do worse. He also admits that Thor is "hot".
* AscendedExtra: He has been hanging around the group since Season 2, showing up a couple of times a year but never really significant. Season 6 practically upgrades him to main cast, at the least supported by WordOfGod that he will have an expanded role. While he didn't stay in the main cast listings for long, unlike Leslie Winkle he still shows up more often than before and usually with a significant role involved.
* ButtMonkey: Everything he says is [[TheEeyore depressing.]] His idea of being "cocky" is to claim that he's "unobjectionable." He can be stood up by a stray cat.
* CharacterizationMarchesOn: In earlier episodes, he was a CoolLoser contrast to the group, but was able to successfully flirt with and ask Penny out. Over time he became a StrawLoser who is even more pathetic and helpless than the main guys, to point he lives in the store due to financial problems and his poverty and depression becoming a RunningGag. At least some of this could be described as a falling out over how his relationship with Penny ended and a series of soul-crushing problems that killed his self-esteem. His social skills have started to come back in "The Bakersfield Expedition" where he chats up the girls while trying to recommend comics for them and repeatedly berates his male customers for leering at them.
* TheChewToy: His life is essentially one misfortune after another.
* TheEeyore: Often comments on how pathetic his life is.
* {{Flanderization}}: He was originally just a very normal guy who successfully asked Penny out. It was a key plot point that in terms of being a decent, normal guy he was virtually identical to Leonard. While he remained a friendly guy he later gained some neurotic ticks, low self-esteem and has a lot more trouble talking to women than before. The change can probably be explained that "nice, normal guy" doesn't leave things too open for comedy and they wanted him to stand apart from Leonard. It's implied in the show that he hit a string of bad relationships in addition to financial problems ''and'' health issues. Getting crushed by Penny (who said Leonard's name while they were making out) in addition to living in the comic book store probably destroyed his self-esteem.
* HeterosexualLifePartners: Interesting in that one of the goals of Season 6 was to have him develop this relationship with Raj, after Howard getting married he could no longer be Raj's "wingman." They are almost never seen separate from each other and there is plenty of HomoeroticSubtext going around.
* HiddenDepths: He is a pretty talented artist.
* NiceGuy: Despite his oddities, Stuart is a very friendly guy and is always willing to help someone out, be it with selecting a comic book or needing a little bit of an emotional boost. He also feeds stray cat, which is quite heartwarming when you consider his financial situation.
* OvershadowedByAwesome: He actually went to the Rhode Island School of Design, a fairly prestigious school and he thus has some genuine skills in art and the average of students accepted into RSID is a B+. But he hangs around Sheldon, who dismisses it as equally ridiculous as Howard's Masters degree from MIT.
* PerpetualPoverty: How little profit the comic book store makes has become Stuart's RunningGag. Among other things, he's mentioned having to sleep in the store, going without meat, and having to shower at Leonard and Sheldon's apartment.
* RecurringCharacter: One of the most frequent recurring characters in Seasons 2-5. In Season 6, he was promoted to series regular, only to be "demoted" back to a frequently recurring character.
* ReplacementGoldfish: Raj basically befriends him to fill the void left by Howard being in space. See SuspiciouslySimilarSubstitute.
* RomanticFalseLead: Dates Penny and Amy for one episode each, both of which force Leonard and Sheldon to reconsider their relationship with those girls.
* ShipperOnDeck: In "The Mother Observation", he admits to shipping Leonard and Penny, saying that each has made the other a better person, and calling them "the best couple I know." (To which Amy and Bernadette react indignantly.)
* SuspiciouslySimilarSubstitute: Serves to fill Howard's spot while he's in space. Sheldon even ''calls'' him, "Fake Wolowitz" at one point.
* ThrowTheDogABone: Kind of a meta-example, ever since Season 3 most of his humor comes from his low self-esteem, poverty, neurosis, medical issues, and even feeling a little lonely despite seeing him with anonymous, nameless friends. While most of that is still his main comedic thrust, as he has become a more prominent character in Season 6, this results in the audience seeing him as having a tight group of friends (the main characters) that invite him to activities and treat him well, Sheldon's jerkass nature notwithstanding. At the end of Season 7, after his comic shop is burned down, Howard offers him a job at taking care of his mother. To everyone's surprise, Stuart likes it.
* UnluckyEverydude: Compared to the other characters, Stuart seems to have ''very'' bad luck. As noted above, his financial situation is almost always precarious at best and the burning down of his beloved comic book store nearly breaks the poor guy. It isn't until he starts caring for Mrs. Wolowitz, a fairly well-paying job Stuart actually enjoys, that his luck finally appears to be turning around.

[[folder:Leslie Winkle]]
!!Leslie Winkle
->'''Played by''' Sara Gilbert
-->You put electrodes in a rat's brain and give him an orgasm button he will press that thing until he starves to death.

A fellow physicist at the university, she has brief romantic relationships with Leonard and Howard, and an intellect and attitude to rival Sheldon. She never passes up a chance to insult him.
* AscendedExtra[=/=]DemotedToExtra: Began to become a more prominent character and was even briefly promoted to main credits, but faded away again when her character proved uninteresting outside of her rivalry with Sheldon.
* BerserkButton: She will do anything to show up Sheldon if he's mentioned.
* BrainyBrunette: Leslie is the first major female example of this until Amy and Alex come along in later seasons.
* CastingGag: Sara Gilbert and Johnny Galecki were married on ''{{Roseanne}}'', Leslie happened to be the first girl of any significance in Leonard's life on the show (aside from Penny).
* CatchPhrase: "Dumbass....."
%% * TheComicallySerious
* DeadpanSnarker: Most of her lines consist of her snarking at Sheldon.
* {{Meganekko}}: Mostly because SmartPeopleWearGlasses. The first {{Meganekko}} to appear on the show before Amy and Bernadette are introduced.
* PutOnABus: Her appearances decrease rapidly once Amy and Bernadette join the cast as regulars. When Leonard turns up at her apartment in Season 3 he mentions that they hadn't spoken in a while, possibly [[JustifiedTrope justifying]] her absence, as it implies that she might have left the university for a new job (since they were lab-mates in the first couple of seasons and would have seen each other at work even if they didn't socialise any more).
* ReallyGetsAround: Leonard describes her as "using sex as a stress release" and she at one point mentions "waking up on a futon with a bunch of guys I don't know".
* ShipTease:
** She and Leonard have hooked up twice, though the first time was purely for the sex, and there have been other hints when they're separated.
** Later she dated Howard for a while, making her the fifth woman to sleep with Howard without being paid.
* SitcomArchnemesis: She strongly dislikes Sheldon and considers him an "arrogant, misogynistic East-Texas doorknob". When she insulted his intelligence, he came to hate her, considering her his "archenemy".
* TheSmartGirl: While most of the characters on the show are very brilliant, Leslie is possibly the only one (along with Amy) who can be considered Sheldon's intellectual equal.
* StaticCharacter: Despite showing a deal of potential as a foil or rival for Sheldon, and amassing a significant fanbase in her own right, the writers never really let her grow from sporadic nemesis. WordOfGod says this was because the writing team found it difficult to expand her character beyond her rivalry with Sheldon.
* TheStoic: She keeps a very straight face most of the time when she isn't being seductive or trying to humiliate someone
* WorthyOpponent: She's as intelligent as Sheldon and their mutual dislike for one another matches them very well in some competitive situations.

[[folder:Barry Kripke]]
!!Barry Kripke
->'''Played by''' John Ross Bowie
-->"We're ''all'' pathetic and cweepy and can't get girls. That's why we battle wobots."

Another rival at the university, he and Sheldon do not get along well at all. Kripke is defined by a speech impediment in being unable to pronounce R's, substituting the sound of a W, making him unable to say his own name properly.
* AlwaysSomeoneBetter: If he's featured in an episode, by the time it ends, he'll have faced at least one of the guys and come out the winner. Most prominent when they face him in a ''Series/BattleBots'' fight, as their robot did well destroying a toaster oven while Kripke's robot "Had angry sex with a Camry!" It could be argued that Barry is the "smartest" character in the series, being the academic equal of Sheldon and a capable engineer (demonstrated with the robot battle); in a sixth season episode, when both have similar proposal for a reactor, Sheldon admitted without any pressure that the Kripke's work was a lot better.
* BunnyEarsLawyer: Has something of a fratboy personality and often crude and obnoxious but is every bit a genius as the rest of the cast. When competing for tenure he also turns up the charm and is apparently great with kids.
* CasanovaWannabe: He tries hitting on Penny in the most obnoxious way, prompting Howard to quip "I'm looking pretty good right now, aren't I?"
* ElmuhFuddSyndwome: He doesn't pwonounce his R's w-ight. And just look at his name.
* FriendlyEnemy: DependingOnTheWriter he is on decent terms with the group as a whole but often ends up as the villain of an episode. Played with when Sheldon believed he held power over the use of the University's supercomputer, thus spent time developing a Friendship Algorithm to become friends with him.
* TheGamblingAddict: Implied, given he willingly went to Sheldon's party only because there's going to be a raffle.
* {{Jerkass}}: Not always (see Took a Level in Jerkass) but he certainly qualifies at times and when he does he becomes the most despicable person in the whole show. He regularly goes out of his way to act as obnoxious as possible towards others including rubbing his success and failures in there face. He never misses a chance to mock, insult or humiliate Sheldon. He's also very perverted and misogynist to the point he makes pre-character development Howard look like a perfect gentleman. He's even able to sometimes surpass Sheldon in this regard.
* LastNameBasis: Nearly always referred to by his last name.
%%* OohMeAccentsSlipping: He's been slipping up quite a bit.
* ProfessionalButtKisser: Not often demonstrated but comes out whenever a promotion of some sort is available at the university.
---> ''If any of you need my nose, you will find it firmwy wodged in the collwective wectums of the tenure committee.''
* RecurringCharacter: He's one of the series' longest running regulars and usually appears at least once or twice per season, although some feature him much more than that.
* TheRival: To Sheldon, being that they both have massive egos and typically get into prank wars or competitions with each other. In his introductory episode, he seemed to be rivals with Howard, given they were both engineers. But in general he is more often a co-worker the group only ''sometimes'' doesn't get along with rather than anything malicious involved, he doesn't quite fit the role of a SitcomArchNemesis.
* TookALevelinJerkass: {{Zigzagged}} When he first appeared Barry though arrogant and jerkish, Barry didn't seem a particularly bad guy, just another scientist on an opposing team. Since then however he's gone back and forth from being a FriendlyEnemy, and a very unpleasant man who seems to exist just to bully Sheldon and rub his failures in his face. One episode took this to whole new level by revealing he regularly embezzled the university, by applying for grants to investigate things he knew he couldn't prove, meaning he is free to spend the money on things for himself.

[[folder:Zack Johnson]]
!!Zack Johnson
->'''Played by''' Brian Smith
-->"I was watching the DiscoveryChannel and they said if you cut a Starfish in half it will just come back to life."

A brief boyfriend of Penny's who becomes friends with the guys. Hopelessly stupid, thinking that bouncing a laser off the moon would be a danger ''to the moon'', he is otherwise a decent guy.
* BrainlessBeauty: Male version, he's outright described as being very handsome by everyone, and is as thick as two short planks.
* CharacterizationMarchesOn: In his first episode, he was a jerk ''and'' an idiot. In later appearances, he's a total sweetie. [[DumbIsGood And an idiot]].
* DumbIsGood: Incredibly dense, but is very open and friendly with the guys.
* HiddenDepths: While he is hopelessly unable to grasp the actual science, he still shows an interest in what the guys are doing and apparently watches the DiscoveryChannel from time to time. He is also very knowledgeable about the designing and creation of restaurant menus.
* KindheartedSimpleton: Simple-minded in nearly every regard, Zach is arguably the nicest person in the series and never once acts malicious or rude towards Penny or the guys. Even ''Sheldon'' starts to restrain himself when Zach makes dense comments, simply because the guy is just too nice and friendly to be mean or blatantly condescending to.
* LiteralMinded: When having gotten in a fight, he knocks on her door...
-->'''Zack:''' Come on babe, open up.\\
'''Penny:''' I'm not talking to you!\\
'''Zack:''' (Genuinely confused) [[LogicBomb Then who are you talking to?]] ...babe?
* NiceGuy: Got upset when he realized the others were mocking him, but [[EasilyForgiven quickly forgave them]] when [[TastesLikeFriendship offered some Milk Duds]]. It's one of the main reasons the guys don't mind having Zach around, and he's incredibly earnest when it comes to their similar nerdy interests.
* NotSoDifferent: Raj bonds with him after realizing that Zack is a comic book aficionado.
* OddFriendship: While the guys initially made fun of his stupidity, they quickly ended up befriending him due to their love of comic books. They continued to hang out even ''after'' Penny had broken up with him.
* RomanticFalseLead: A rather triumphant example, as he slowly bonded with the rest of the main characters despite largely being there to provoke some awkwardness between Leonard and Penny. He avoids the traps of being either too obnoxious (wondering why Penny is bothering with him) or being too decent of a guy (making him seem too appealing) by making it so that he and Penny did not have a whole lot of chemistry, so the focus was on the awkwardness and not worrying about hurting his feelings. The fact he was also pretty funny made him something of an EnsembleDarkhorse, and not just for {{Shipping}} reasons.
* SarcasmBlind: To the point that Sheldon seems like an expert.

->'''Played by''' Vernée Watson
-->''I'm sorry, we don't have a code for "robot hand grasping a man's penis."''

Desk nurse at the local hospital, who has to deal with/knock sense into the guys whenever their [[ZanyScheme Zany Schemes]] land them there. Also appears in the very first scene of the pilot as the receptionist at the sperm bank Leonard and Sheldon go to.
* ComicallySmallBribe: She turns one down offered by Howard:
-->'''Howard:''' What if I were to introduce you to ''(holds up bill)'' the man who freed your people?\\
'''Althea:''' Unless my people were freed by Benjamin Franklin[[note]]100 dollar bill[[/note]] and his five twin brothers, you are wasting your time!
* DeadpanSnarker: ''Everything'' she says is snarky. It's what makes her so memorable as a character, despite having only four appearances (so far).
* SassyBlackWoman: Oh so much. She's 100% willing to call the guys out on their stupidity and loads on the sass while doing it.
* WomenAreWiser: When Howard comes in with the robot hand stuck on his privates, Althea immediately finds the solution that could have saved him a lot of embarrassment: simply turning the robot off and then on again.

[[folder:Wil Wheaton]]
!!Wil Wheaton
->'''Played by''' Creator/WilWheaton
-->"Don't worry, it [being Sheldon's mortal enemy] doesn't take up too much of your time."

A local celebrity and perpetual rival to Sheldon, after an incident where he bailed out on a Franchise/StarTrek convention Sheldon suffered great things to attend.
* AdamWesting: Takes it to a new art form.
* ArchEnemy: Sheldon considers him this in his earlier appearances, owing to his failure to attend a Comic-Con convention a number of years previous, which Sheldon attended in hopes of an autograph. They eventually become friends though.
* TheAtoner: Shows signs. He invited Sheldon and his friends to a party -- and when Sheldon actually shows up, Wheaton gave Sheldon a signed action figure to make up for not showing up at the ''Franchise/StarTrek'' convention Sheldon went to as a child. [[spoiler: Of course, [[Series/StarTrekTheNextGeneration Brent Spiner]] ended up inadvertently ruining the gesture by opening said action figure]], but at least Wheaton is off Sheldon's ArchEnemy list. He later seemed to be on good terms with him at Howard's Bachelor Party. He later appears at on Sheldon's 'Fun with Flags' webshow, unintentionally causing trouble with Sheldon's relationship to Amy, ending with Sheldon throwing up in his rosebush. He's still friends with Sheldon as of the Season 7 finale.
* BeardOfEvil: Has stubble, but still keeps it after he stops being evil.
* EvilGloating: Gloats that being Sheldon's archnemesis means he lives in Sheldon's head ''rent free''.
* HeelFaceTurn: He eventually goes back on his original jerkish behaviour and forms a friendship with not just Sheldon, but all the others. See TheAtoner.
* {{Jerkass}}: Originally he was a very big jerk being willing to lie through his teeth to win a contest, and exploit his celebrity status just to spite Sheldon, but he grew out of it in Season 5.
* JerkWithAHeartOfJerk: In his early appearances, he lied about his grandmother dying to win a card game, cheated the gang out of there movie seats (after literally hours of waiting in line) and managed to convince Penny to break up with Leonard so he could win a bowling match. However he stopped being this after his HellFaceTurn.
* KarmaHoudini: Regardless of the episode and what he does specifically, Wheaton typically causes trouble for the group and specifically Sheldon and never gets any retribution. He breaks up Leonard and Penny to win a bowling match and wins. There's a certain part of the fandom that wants Penny to figure out he did it on purpose and get her revenge.
* ManipulativeBastard: In his early appearances. He deliberately starts an argument between Penny and Leonard so that his bowling team can beat Sheldon's.
* NiceCharacterMeanActor: In the show's universe, Wheaton is a selfish, scheming mastermind SitcomArchnemesis who orchestrated the first break-up between Penny and Leonard just to beat Sheldon's team at bowling -- a far cry from his character on ''[[Series/StarTrekTheNextGeneration Star Trek]]'' (which is how Sheldon initially knew of him).
* MeanCharacterNiceActor: Which in turn results in this, since in real life Wheaton is known to be a nice guy.[[note]]Because of this, Wheaton's Law (originally "Don't be a dick") was refined to "Don't be a dick, but it's okay to play one on TV.[[/note]]
* TookALevelInKindness: He's not as antagonistic as he was in earlier seasons. He seems to have dropped his feud with Sheldon as well.

[[folder:Alex Jensen]]
!!Alex Jensen
->'''Played by''' Margo Harshman
--> "All I know is that corduroy makes too much noise. If you'll excuse me I have to go find quieter pants."

A grad student Sheldon hires as an assistant. Friendly with the group, she is at least somewhat capable of dealing with her boss' many eccentricities. Which gets harder to do as time goes on.
* BrainyBrunette: Smart enough to earn Sheldon's regard.
* ButtMonkey: Only natural since she has to be Sheldon's assistant.
* LoveAtFirstSight: Raj immediately gets a crush on her, though as usual he is incapable of talking to her.
* PuppyDogEyes: Which make Sheldon's abominable treatment of her more annoying.
* ShipTease: Between her and Leonard. Alex obviously has a crush on him and keeps hitting on him, which he didn't realize at first.
* TomboyishName: Along with the requisite gender confusion when Amy learns Sheldon's new assistant Alex is female. Penny laughs hysterically when Amy gets worried about the implications: "He didn't tell me Alex was a girl." "[[{{Asexual}} Maybe he didn't notice]]."
* UnknownRival: To Penny. Alex obviously likes Penny's boyfriend.
* WhatHappenedToTheMouse: After the Valentine's Day episode "The Tangible Affection Proof", she makes no more appearances. It's possible that after taking so much of Sheldon's crap that she quit.

->'''Played by''' Kate Micucci

A timid girl Raj met at a [[{{Irony}} "Lonely Hearts"]] valentines party. She is painfully awkward and shy but tries to get through her neurosis by going outside her comfort zone.
* {{Adorkable}}: In a way only Kate Micucci can pull off. She's extremely shy and awkward, but Raj genuinely likes her looks and personality. They spend one date night just texting, and both love it.
* BrokenBird: After some prodding she confessed she was broken and simply not comfortable around people.
* KickTheDog[=/=]PetTheDog[=/=]ShootTheShaggyDogStory: One of the first things she does is bail out of her first coffee date with Raj, which sends him into depression. [[TheAtoner She later tracks him down to apologize]] and explains that she has trouble talking with people. In the Season 6 finale, [[spoiler:she breaks up with him via a text message.]]
* TheReasonYouSuckSpeech: She receives a brutal one from Penny, who calls out her habit for bailing too quickly [[spoiler:in her relationship with Raj.]] Penny even flat-out calls her "a bad person."
* ShrinkingViolet: To the point where it destroys her relationship with Raj. Her anxiety is so terrible that she literally can't handle being around more than one person at a time and panics ''every'' time Raj attempts something outside of her comfort zone.
* WhamEpisode: The Season 6 finale, when [[spoiler:she breaks up with Raj, curing him of his selective mutism.]]

[[folder: Janine Davis]]
!!Janine Davis
->'''Played By''' Regina King

The Human Resources director at [=CalTech=] and on the tenure committee. Given the quirks of the main characters, she finds herself having to counsel them often on what is and is not appropriate behavior in the workplace. She was very familiar with Howard before he got married.
* FacePalm: Especially when having to deal with [[NoSocialSkills Sheldon]].
* ShipTease: Raj has expressed some attraction to her (thus also making it somewhat TokenShipping), although it is greatly one sided.
* SurroundedByIdiots: Has frequent run-ins with the guys, in particular Sheldon, who somehow manages to stumble blindly into incredibly racist comments without meaning to.
* TokenMinority: Certainly notable among the recurring characters (the show has had plenty of minority characters but besides Raj they haven't been more than one episode). Sheldon also tends to single her being black as a character trait, not understanding why ''Series/{{Roots}}'' may not be an appropriate or insightful gift to give her.
* YourCheatingHeart: Her husband apparently left her for an undergrad student.


[[folder:"Professor Proton"]]
!!Arthur Jefferies/"Professor Proton"
->'''Played by''' Bob Newhart
-->"If I had known people would be calling me "Professor Proton" into my 80's, I wouldn't have quit smoking."

A children's [[EdutainmentShow science show]] host 30 years ago, he was invited by Sheldon to perform a "birthday party" science demonstration for the group. He is bitter that despite being a degree'd professional with a Ph'D in physics, none of his later work was taken seriously because he was a kids show host. He appreciates the attention and respect Sheldon and Leonard give him, though is easily annoyed with Sheldon's hero worship. He passed away after several appearances in the show, but continued to manifest as a SpiritAdvisor to Sheldon.
* CoolOldGuy: Once you get past the grumpiness, he is very friendly.
* DirtyOldMan: Downplayed. He obviously enjoys hanging around Penny more than the guys, but he isn't quite creepy about it.
* GrumpyOldMan: Overall bitter about life and his age, not helped by Sheldon's obnoxiousness.
* RealisticDictionIsUnrealistic: As per being played by Bob Newhart.
* TheObiWan: Referenced by name, Sheldon tries to be strong about it like Luke but comes to realize via Proton as his SpiritAdvisor that pushing away the people who care about him won't make it easier to deal with the death of loved ones.
* OldShame: [[invoked]] Has regrets over his career path after doing the show, while Leonard and Sheldon help him see many modern scientists were inspired by his work as kids.
* ScrewPolitenessImASenior: Generally good-natured, he can get grumpy.
* SitcomArchNemesis: With Series/BillNyeTheScienceGuy.
-->'''Bill Nye:''' Wow, Arthur Jeffries. It's an honor to meet you. My show never would have happened without yours.\\
'''Arthur Jeffries:''' That's what I told my lawyers.
* SpiritAdvisor: After he died, he showed up in Sheldon's dream. Both he and the manifestation of Arthur are trying to figure out what he must be coming back to help Sheldon with.
* StylisticSuck: His show was pretty silly, but it seemed a lot of its charm was how annoyed he was with the writing.

[[folder: Emily Sweeney]]
!!Emily Sweeney
->'''Played by''' Laura Spencer

Raj's love interest, starting Season 7. Seemingly an OfficialCouple with him as of Season 8.
* CuteButPsycho: She's very lovely, but has a rather disturbing side as well. She once remarked she became a dermatologist because it's a line of work where she's allowed to cut people. It could have been a morbid sense of humour, but it's a bit scary. She has a tattoo of Sally from Nightmare Before Christmas on her shoulder blade because she likes the fact she's covered in scars and can pull her own limbs off and sew them back on.
* ForgottenFirstMeeting: She and Howard first met on a blind date. Apparently, Howard had a stomach problem that ended in her toilet being clogged, and him sneaking out the bathroom window in embarrassment. Thus, he was nicknamed "[[EmbarrassingNickname Clogzilla]]".
* HospitalHottie: She's a Dermatologist and very attractive, though we mostly see her outside of the workforce so her primped appearance is justified.
* IvyLeagueForEveryone: She went to Harvard.
* LoveInterest: She contacted Raj over online dating site and he immediately developed a crush on her.
* MeaningfulName: Let's see. She likes to cut people up, and her name is [[Theatre/SweeneyToddTheDemonBarberOfFleetStreet Sweeney]].
* NiceGirl: She appears to be a nice lady, acting very friendly and accepting towards Raj and the others.
* NightmareFetishist: Has confessed that gory movies turn her on.

[[folder:Stephen Hawking]]

The world famous physicist himself. First featured when Howard was assigned to help maintain his communication and life support systems when he visited the university, he has since made irregular cameo appearances.


* AsHimself: It's the real Stephen Hawking.
* DeadpanSnarker: He has a ''mean'' wit.
--> '''Sheldon:''' Buh-buh-but there has to be a mistake! I don't make mathematical errors!
--> '''Hawking''': Are you saying that ''I'' do?
* LivingLegend: The guys, being scientists themselves, naturally admire his genius and absolutely squee over him when he appears at Caltech for the first time. Even Sheldon craves his approval.
* SitcomArchnemesis: To an extent, he does antagonise Sheldon, however Sheldon idolises him so it's solely one sided.
* {{Troll}}: He loves antagonizing and mocking Sheldon. In "The Troll Manipulation" he justifies it as "if you were sitting in a chair for forty years, you'd get bored, too."
--> "What do Sheldon Cooper and a black hole have in common?…They both suck….{{Beat}}…neener, neener."