This is a list for the [[LoadsAndLoadsOfCharacters large and varied cast]] of Nickelodeon's ''HeyArnold''.

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[[folder:Students of P.S. 118]]

!! Arnold [[spoiler:Shortman]]

[[quoteright:230:http://static.tvtropes.org/pmwiki/pub/images/hey-arnold-09_1282.jpg]]

-> Voiced by: J.D. Daniels (original pilot); Toran Caudell (season 1 and "What's Opera, Arnold?"); Phillip Van Dyke (seasons 2 and 3); Spencer Klein (seasons 4, 5, and TheMovie); Rusty Flood ("Helga on the Couch" and "Parents Day"); Alex D. Linz ("The Journal" and "April Fool's Day")

* AdorablyPrecociousChild
* AllLovingHero
* BelligerentSexualTension: With Helga.
* BlitheSpirit: Most of the time he does some miracle with someone's life.
* CharacterizationMarchesOn: He was more eccentric and naive early on. Midway in Season 3, this began to change.
* ChickMagnet
* CloudCuckooLander: In the early seasons, anyway.
* TheConscience: To everyone, especially in later seasons.
* DeadGuyJunior: He was named after his mother Stella's late father.
* DoggedNiceGuy: When he realizes that he likes Lila.
* [[EtTuBrute Et Tu, Iggy?]]: Happens to him in the episode, "Arnold Betrays Iggy", when he was forced by him to wear his bunny pajamas. This is the reason why many fans hate that episode. [[spoiler:even Craig Bartlett and the producers hate it. So they made it like a "lost episode"]]
* TheEveryman: Eventually in the later seasons.
* {{Flanderization}}: His natural desire to help people and incorruptible personality really took over.
* FourTemperamentEnsemble: The Phlegmatic.
* GenerationXerox: In "Girl Trouble," it's revealed his grandparents had a relationship very similar to the one he has with Helga when they were younger.
* GreenEyes: According to a poem by Helga.
* HairOfGoldHeartOfGold
* TheHeart
* HeroesWantRedheads: He has a crush on the auburn-haired Ruth and later on the bright redhead Lila.
** But according to Phoebe in "Ruthless," Ruth's hair is chestnut.
* HeterosexualLifePartners: With Gerald.
* IdealHero
* LikesOlderWomen: Up until Lila showed up, he had a crush on an older girl, and in one episode was infatuated with the substitute teacher.
* LivingEmotionalCrutch: Helga says she would probably go crazy if it weren't for Arnold.
* LovingAShadow: with Ruth, but also in general, he easily falls in love without knowing his beloved.
* MasculineGirlFeminineBoy: Feminine Boy to Helga's Masculine Girl.
* NiceGuy: His defining character trait. Even when he's not the focus of an episode, he'll usually be the only one who won't make fun of the episode's protagonist
* NiceHat
* ObliviousToLove
* OnlyOneName: The creator ''almost'' confirmed that his last name is [[spoiler:Shortman]], and it's PlayedForLaughs.
-->'''Announcer:''' And the winner is...Arnold...hm. The last name appears to be smudged.
-->'''Stinky:''' That must be you, Arnold, on account of you're the only Arnold in the entire school.
* OnlySaneMan: Amongst his class mates, though Gerald isn't that far behind.
* ParentalAbandonment: Living with his grandparents, Arnold's DisappearedDad and MissingMom are not even alluded to for a good portion of the series. We eventually learn they disappeared during a jungle expedition while Arnold was a baby.
* PinkGirlBlueBoy: Blue Boy to Helga's Pink Girl.
* RaisedByGrandparents
* TragicKeepsake: His hat, which was given to him by his parents. When he loses it in one episode, he's determined to get it back.
* WideEyedIdealist
* WiseBeyondHisYears: To the point that just about everyone on the show, including adults and even authority figures, have come to him for advice.

!! Helga G. Pataki

[[quoteright:195:http://static.tvtropes.org/pmwiki/pub/images/Brainy_punched_7762.jpg]]

-> Voiced by: Francesca Marie Smith; Katie Bartlett ("Helga on the Couch")

* AccidentalPervert: When she snuck into Arnold's room, she was stuck between the the wall the couch folds into. She ended up seeing Arnold disrobe, [[TemptingFate even though she didn't mean to.]]
* AntiHero / AntiVillain: Depending on the episode. Earlier episodes tended to use the latter, while later episodes mostly had her be the former.
* AwLookTheyReallyDoLoveEachOther: With Olga.
* BecauseYouWereNiceToMe: Helga fell in love with Arnold because he was the first person in her life that noticed her and treated her kindly.
** In somewhat of an inversion, this is why she treats Arnold like garbage.
* BelligerentSexualTension: With Arnold.
* BeneathTheMask: She pretends to hate Arnold to hide her true feelings for him, and only expresses said feelings when she's alone. Or she thinks so, and Brainy [[OffscreenTeleportation teleports]] behind her.
* BettyAndVeronica: The Veronica to Lila's Betty for Arnold's Archie.
* TheBigGirl
* BigOlUnibrow
* BlondesAreEvil: PlayedWith. She's not evil ''per se,'' but she's not very nice.
* BreakoutCharacter: Helga grew in popularity due to her compelling CharacterDevelopment. By the end of the series, most people would think ''she'' was the main character instead of the football head due to how much spotlight she had. In fact, the show was meant to have a sequel specifically geared around Helga as the main focus in high school.
* BrilliantButLazy: Though not a perfectionist like Olga, the aptitude test shows she '''is''' nearly as competent.
* BrokenBird: Of the {{badass}} variety. She mentions in one episode that she would probably go crazy if it weren't for Arnold.
* CannotSpitItOut: And when she did it in TheMovie... she took the chance Arnold gave her to deny it.
* CatchPhrase: "Criminy."
** "Move it, Bucko!"
* CerebusRetcon: [[HilariouslyAbusiveChildhood Much of her background]] becomes unfunny after "Helga On The Couch".
* ClingyJealousGirl: She often tries to [[RelationshipSabotage ruin Arnold and Lila's time together]] because she wants to be the one going out with Arnold.
* DeadpanSnarker
* {{Deuteragonist}}
* DoubleStandardAbuseFemaleOnMale: If her and Arnold's genders were reversed, her abusive tendencies towards Arnold wouldn't be quite as funny.
* DramaQueen: Even taking into account her usual hamminess and issues, she's usually the first person to crack up and go melodramatic in a crisis. (Ironic, considering she's considered the toughest girl in school behind Big Patty.)
--> (when stuck on the other side of town) '''''"Walk!?''''' It'll take ''days!'' We'll ''freeze to death! '''WE'LL GET EATEN ALIVE BY PIGEONS!''' Or worse... ''rats!"''
* EvenEvilHasStandards: Does some nasty things to Arnold, but takes major offense to her father calling Arnold an orphan within ear shot of him. In "Curly's Girl", Helga calls out on Rhonda for embarrassing Curly after dumping while pretending to be Curly's girlfriend.
-->'''Helga''': I think Miss Rich and Fancy did a number on him, (referencing to Curly).
-->'''Rhonda''': May I borrow the black paint?
-->'''Helga''': ''(paints a heart with the black paint)'', perfect, it'll match the color of your heart.
-->'''Rhonda''': ''(annoyed)'', excuse me!
-->'''Helga''': You heard me Cruella.
* EvilLaugh: Has a very impressive one. Not as psychotic as Curly's (but then, who could be), but she gets points for once doing it in a theatre, with ominous music and everything.
* EvilPlan: She explicitly refers to them as such, and she has a ton of them. They nearly always fail in ways that harm her and help those she schemes again.
--> '''Helga:''' [[LampshadeHanging "Why are none of my evil schemes working?!"]]
** Ironically, in the "The Summer House", her schemes to sabotage Arnold and Summer's dates ''do'' work, but Arnold catches her gloating about it and [[CassandraTruth won't listen to her when she tries to tell him Summer is just using him.]]
* FailureIsTheOnlyOption: Her AnguishedDeclarationOfLove in TheMovie. Arnold ends up confused about it.
* FemininityFailure: In "Helga's Makeover", she tries to be a girly girl to attend Rhonda's sleepover but reverts to her old self after refusing an avocado cream mask.
* {{Foil}}: To four characters.
** BeautyBrainsAndBrawn: The Brawn to Lila's Beauty and Phoebe's Brains.
** BlondeBrunetteRedhead: The Blonde to Phoebe's Brunette and Lila's Redhead.
** ChromaticArrangement: Pink to Phoebe's Blue and Lila's Green.
** MasculineGirlFeminineBoy: Masculine Girl to Arnold's Feminine Boy.
** PinkGirlBlueBoy: Pink Girl to Arnold's Blue Boy.
** ShadowArchetype: Helga is, [[{{Irony}} ironically]], Brainy's shadow.
** TomboyAndGirlyGirl: Tomboy to Phoebe and Lila's Girly Girl.
** TownGirls: The Butch to Phoebe's Neither and Lila's Femme.
* ForcefulKiss: Gives a big one to Arnold in TheMovie.
* FourTemperamentEnsemble: The Choleric.
* FreudianExcuse
* TheGloriousWarOfSisterlyRivalry: With Olga.
* InLoveWithLove: Requited or not, pining itself is important to her.
* HairDecorations: She always wears her trademark pink bow, presumably because Arnold complimented it when they first met.
* HatesBeingTouched
* HeterosexualLifePartners: Her and Phoebe - mirroring Arnold and Gerald.
* HiddenDepths
* HilariouslyAbusiveChildhood: At least until "Helga On The Couch".
* {{Hypocrite}}: What Helga feels and how Helga acts are always opposite things.
* {{Jerkass}}
** JerkassFacade
** JerkWithAHeartOfGold: She does care about people, even if she doesn't show it.
* TheLadette: A pre-teen version.
* LargeHam: A running gag is her tendency to break into overly melodramatic monologues whenever she does anything she regrets, as well as villainous monologues when she's scheming. Often complete with theatrical music.
* [[LikeFatherLikeSon Like Father, Like Daughter]]: Personality-wise, she actually has a lot in common with Big Bob, but Helga is much more articulate and emotional.
* LittleMissSnarker
* LovingBully: The poster girl.
* MysteriousMiddleInitial: What precisely the "G" stands for is never revealed in-series; it's actually short for "Geraldine", as a tribute to then-{{Nickelodeon}} executive Geraldine Laybourne.
** Considering how many times she's diminuatively called Gerald "Geraldo"...
* TheNicknamer: She has a name for everybody.
* OffhandBackhand: Helga frequently does this to Brainy.
* PerpetualFrowner
* PetTheDog: Several times, like in "Arnold's Christmas"
* PinkMeansFeminine: Subverted. She wears a pink dress as well as a pink bow in her hair but she's rather tomboyish.
* TheReasonYouSuckSpeech: Helga is pretty good at these; She gives a pretty cutting one to Miriam about her being a "lousy mom", and one to Harold after he gets them lost.
* SheCleansUpNicely: Most of the time she doesn't care how she looks, but when she tries (and knows what she's doing) she looks gorgeous.
* SingleTargetSexuality: Never shows the slightest interest in anybody but Arnold.
* SingleWomanSeeksGoodMan
* SlapstickKnowsNoGender: Very often. [[DeconstructedTrope Deconstructed]] in "Helga On The Couch".
* SourOutsideSadInside
* SpotlightStealingSquad: More episodes focused on Helga than any other character except for Arnold, and that's ''not'' including the ''many'' Arnold/Helga episodes.
* StalkerShrine: Hers is the Trope picture.
* StalkerWithACrush
* StepfordSnarker: Due her backstory.
* TomboyWithAGirlyStreak: For all her tomboyish and violent personality, Helga always wears pink dresses, her room is filled with girly stuff and is a hopeless romantic.
* '''{{Tsundere}}''': Type A. Oh so much, until TheMovie.
* TheUnfavorite
* UnknownRival: Lila has no idea that Helga hates her at all, let alone why. Ironically she likely wouldn't want to be considered Helga's rival for Arnold's affections at all, since she doesn't reciprocate.
* UnsympatheticComedyProtagonist
* VitriolicBestBuds: Type 1 with Phoebe
* WellDoneDaughterGal: She wants her the approval and attention of her parents (particularly Bob), but she rarely ever gets it due to being TheUnfavourite.

!! Gerald Johanssen

[[quoteright:160:http://static.tvtropes.org/pmwiki/pub/images/Gerald5_6007.jpg]]

-> Voiced by: Jamil W. Smith

Best friend to Arnold.

* AwLookTheyReallyDoLoveEachOther: Like Helga, he clashes with his older sibling, Jamie O., but in "Jamie O. in Love", Jamie O. gets a girlfriend, causing Jamie O. [[LoveMakesYouDumb to act like a happy ExtremeDoormat]], which Gerald takes advantage of, but when it turns out she is just using him, Gerald begrudgingly tells him the truth.
* BeehiveHairdo: It's apparently an exaggerated hi-top fade, a style that was popular in the 90s.
* BerserkButton: He gets ''really'' angry with [[BigBrotherBully Jamie-O]] when he thinks he's trying to "steal" [[OneshotCharacter Chloe]].
* BetaCouple: With Phoebe.
* BlackBestFriend
* DeadpanSnarker
* FourTemperamentEnsemble: The Sanguine.
* HeterosexualLifePartners: With Arnold.
* TheLancer
* LargeHam: Any time he's in front of a crowd. Does everything from reciting cheesy UrbanLegends to reading a list of fun things to do on Saturday with all the passion and soul of a gospel preacher.
* SoulBrotha
* TheSmartGuy: Generally is one of the most informed and competent of the kids.
* TheSocialExpert: He is an extremely convincing businessman, gives Arnold dating advices and of course, is a talented [[TheStoryteller performer]] when it's needed.
* TheStoryteller: Whenever an urban legend or old story needs to be told, Gerald fulfills this role. He is "the keeper of the tale" for many tales.

!! Phoebe Heyerdahl

[[quoteright:160:http://static.tvtropes.org/pmwiki/pub/images/Phoebe_101.jpg]]

-> Voiced by: Anndi [=McAfee=]

Best friend of Helga. Half Japanese girl who was born in Kentucky but moved to the city at a very young age.

* {{Adorkable}}
* AsianAndNerdy
* BeautyBrainsAndBrawn: The Brains to Lila's Beauty and Helga's Brawn.
* BerserkButton: She seems to have a mild one connected to when someone outperforms her academically or socially. In "Phoebe Cheats," she plagiarizes a poem for a contest presumably because Sheena got a higher grade than she did, and because she wasn't chosen as a Student of the Month.
* BetaCouple: With Gerald.
* BewareTheNiceOnes: Pushing her around too much is not a good idea.
* BlondeBrunetteRedhead: The Brunette to Helga's Blonde and Lila's Redhead.
* BrainyBrunette
* BrokenPedestal: She was crushed when she realized Ronnie Matthews was a shallow jerk.
* ButNotTooForeign
* Catchphrase: In response to Helga asking her to do something: "[verb]-ing!" In particular, there's...
** PhraseCatcher: ...this exchange:
--> '''Helga:''' "Oh, and Phoebe? This conversation never happened."
--> '''Phoebe:''' "Forgetting!"
* CharacterizationMarchesOn: In the first season she was a lot more of a SatelliteCharacter to Helga, to the point of more or less being her shadow and not having much character herself. Later seasons fleshed out her personality more and made her less of a "minion" type.
* ChromaticArrangement: Blue to Helga's Pink and Lila's Green.
* CuteBookworm
* ExtremeDoormat: To Helga.
** OutOfCharacterMoment: In "Helga and the Nanny", she along with Arnold, Stinky, and Gerald walk out on Helga upon learning what she did to Inge.
** She also has one of these moments in "Ms. Perfect," when she participates in the initial tormenting of Lila.
*** When she gets skipped ahead to the Sixth Grade, she is "befriended" by a group of girls who just want Phoebe to do their homework for them. Helga even points out they're just using her.
* FourTemperamentEnsemble: The Melancholic.
* HeterosexualLifePartners: With Helga.
* HiddenDepths: She's great with a fencing sword and speaks fluent Japanese. Both traits are nurtured by her Japanese-American dad.
* KnightTemplar: As a hall monitor. Snaps out of it at the end of the episode.
* TheLancer: To Helga, occasionally.
* {{Meganekko}}
* NiceGirl
* {{Sidekick}}: Though she hates being treated like one, she often fills this role. As her character is fleshed out more it's shown more clearly that it is due to her being an extremely loyal - and patient - friend.
* OOCIsSeriousBusiness: In "Hall Monitor", when she became said job, she [[TookALevelInJerkass took it Helga training to much]] to the point Helga had to [[MyGodWhatHaveIDone realize this]] and take action.
* SecretKeeper: One of the few characters who knows about Helga's crush on Arnold.
* TheSmartGirl
* TomboyAndGirlyGirl: Girly Girl to Helga's Tomboy (One of two).
* TownGirls: The Neither to Helga's Butch and Lila's Femme.
* TrueBlueFemininity
* VitriolicBestBuds: Type 1 with Helga (receiving end).

!! Rhonda Wellington Lloyd

[[quoteright:266:http://static.tvtropes.org/pmwiki/pub/images/Rhonda_8221.jpg]]

-> Voiced by: Olivia Hack

One of the most popular kids in school and self-proclaimed "fashion queen", Rhonda is spoiled, rich, obsessed with fashion, and is a bit of a snob, but she does have a friendly side that comes out quite often. Her best friend is Nadine, but she's often seen hanging out with Arnold and the gang. It's implied that she and Harold like each other, and Curly likes her too... [[AbhorrentAdmirer much to her chagrin]]. She's also a surprisingly good football player.

* AlphaBitch: Very often.
* BreakTheHaughty: All the freaking time, but most notably ''Rhonda's Glasses'' and ''Rhonda Goes Broke''.
* FallenPrincess: This is the subject of a couple episodes (most notably "Rhonda's Glasses" and "Rhonda Goes Broke"), but she's always back on top by the end.
* TheFashionista
* HeroicBSOD: When her family goes poor in [[ExactlyWhatItSaysOnTheTin "Rhonda Goes Broke"]] - specifically, when everybody finds out that she's poor - Rhonda has a major one, spending all her time in her room miserably crying. Luckily, Arnold reboots her when he talks some sense into her and asks if being rich is ''all'' she's about.
* HypocriticalHumour: In one episode, she tells Nadine she has to have a "three shoe rotation" in order to continue hanging out with her, even though all the characters in the show, including Rhonda, have a LimitedWardrobe.
* JerkWithAHeartOfGold: She does have a good heart under her vain, self-centered exterior.
* LargeHam: She's pretty prone to this when she breaks into histrionics, especially in the episode "Rhonda Goes Broke".
* LovableAlphaBitch: Despite often being a typical spoiled rich girl, she does have a kind side. Not only does she always do the right thing in the end, but her best friend - Nadine - is middle-class.
* {{Meganekko}}: In "Rhonda's Glasses".
* OddFriendship: With Nadine, but they've been friends since they were little.
* RichBitch: On her worst days.
* SpoiledSweet: On her best days.
* TomboyAndGirlyGirl: Girly Girl to Nadine's Tomboy.
* {{Tsundere}}: For Harold.
* UnwantedGlassesPlot: Gets them in ''Rhonda's Glasses'', but later replaces them with cooler glasses, and eventually contacts.

!! Nadine
[[quoteright:200:http://static.tvtropes.org/pmwiki/pub/images/nadinebeetle_2171.jpg]]
-> Voiced by: Lauren Robinson

Nadine is Rhonda's best friend, [[OddFriendship even though they couldn't be more different]]. She is fascinated by bugs and arachnids.

* DarkSkinnedBlonde
* FreakyIsCool: Yay, bugs!
* FriendToBugs
* GirlishPigtails: Though they're meant to resemble spider legs.
* OddFriendship: With Rhonda.
* SatelliteCharacter: To Rhonda.
* TomboyAndGirlyGirl: Tomboy to Rhonda's Girly Girl.

!! Harold Chaim Berman
[[quoteright:200:http://static.tvtropes.org/pmwiki/pub/images/haroldmarch_5318.jpg]]
-> Voiced by: Justin Shenkarow

A fat kid who's been held back a few grades. Occasionally, a bully.

* BareYourMidriff: Because he's so fat his shirt doesn't fit him properly.
* BerserkButton: Yeah, keep calling Patty "Fatty Patty." That's a good way to induce Harold's biggest screaming meltdown of the series.
* BigEater
* TheBigGuy: He even gets into trouble in one episode because he steals a ham from Mr. Green. When confronted by his parents, he replies, "''I was hungry!''"
* BigOlUnibrow
* CatchPhrase: ''"Madame Fortress Mommy!"'' [[ThrowItIn Adlibbed]] by Justin Shenkarow once to Craig and everyone's amusement. They kept writing it in after.
* DumbMuscle
* HeldBackInSchool: Is about 13 years old (old enough to have a bar mitzvah) but still in 4th grade.
* HiddenDepths: Usually with Harold what you see is what you get. But after a mix up in "The Aptitude Test" results in him believing he's a genius, he starts listening to classical music, correctly solves a math problem in his head, and designs a gazebo/bonsai garden for his family's rooftop.
* InformedJudaism: His Jewish background wasn't mentioned until the episode in which he tries to run away from his own bar mitzvah, though prior to that, it was established he had a mom who acted like a JewishMother.
** In fact, in one of the old claymation shorts, he attends church with Arnold.
* JerkWithAHeartOfGold
* KindHeartedCatLover: Surprisingly, but "Harold's Kitty" has him adopting a seemingly stray cat and fawning over it.
* LargeHam
* NiceHat
* NoIndoorVoice
* OnlyKnownByTheirNickname: His given Hebrew name is Chaim, but he prefers to be called Harold.
* SheIsNotMyGirlfriend: With Patty.
* ShipTease: With Patty, and Rhonda in some episode.

!! Sid
[[quoteright:200:http://static.tvtropes.org/pmwiki/pub/images/sidgogoboots_650.jpg]]
-> Voiced by: Sam Gifaldi; Taylor Gifaldi ("April Fool's Day")

A paranoid boy in a hat.

* CatchPhrase: "Boy howdy"
* ChronicBackstabbingDisorder
* TheDandy
* GagNose
* HollywoodVoodoo: Thought he once killed Principal Wartz with a voodoo doll made of soap.
* IconicItem: His white Beatle boots.
* {{Jerkass}}: His spotlight episodes tend to display him as a paranoid LargeHam who frequently lets his imagination get the best of him or digs himself in too deep and needs Arnold to save him.
* LargeHam: Episodes centering around him bring this out, especially "Sid the Vampire Slayer" and "Sid's Revenge."
* MyGodWhatHaveIDone: When he thinks he's killed Principale Wartz with a voodoo doll carved from soap.
* NiceHat
* OnlyOneName: The second most prominent example on the show, behind only Arnold himself.
* PetTheDog: He's not all bad, however. In one episode, he gets into trouble with Big Gino. When Arnold tells Sid he doesn't have to do what Big Gino says, Gino orders him to give Arnold a swirlie. Sid stands up to Gino to take Arnold's place.
* ProperlyParanoid
* WithFriendsLikeThese: Shares this status with Stinky as two of the worst of the kids besides Helga and Harold. Whereas Helga and Harold both have considerable amounts of depth, Sid and Stinky frequently display LackOfEmpathy and turn on their so-called friends. Notably whenever an episode focuses on Harold, Sid and Stinky while be there to mock him until he finally gives a BigShutUp and threatens to beat the snot out of them.

!! Stinky Peterson
-> Voiced by: Christopher P. Walberg

A kid from Arkansas with a thick Southern accent.

* CatchPhrase: "This really bites."
* CharacterDevelopment: In Season One, he was more of a mindless lackey to Harold and wore spiky arm-bands. Later on, he was revealed to be a lot nicer and no longer wore the arm bands.
* CountryMouse
* GagNose
* GreenThumb: In "Stinky's Pumpkin", he successfully grows an enormous pumpkin that is big enough for him to comfortably sit in.
* IJustWantToBeSpecial
* SimpletonVoice
* TrademarkFavoriteFood: Lemon pudding
* WithFriendsLikeThese: Shares this status with Sid. Although, his spotlight episodes do show he has some depth to him.
* SimpleMindedWisdom
* StrongFamilyResemblance: He looks a lot like his Dad.
* ToxicFriendInfluence: He's nicer when he's not with Sid or Harold.
* VerbalTic: "I reckon".

!! Lila Sawyer
-> Voiced by: Ashley Buccille

A poor country girl who transfers to the school.

* TheAce: Averted in "Ms Perfect"- the others girls think she's this, causing them to bully her, but then they find out Lila is very poor and no longer has a mother, making them have a collective MyGodWhatHaveIDone.
* AllLovingHero: Although she came off as an intentional [[ParodySue parody]].
* BeautyBrainsAndBrawn: The Beauty to Phoebe's Brains and Helga's Brawn.
* BeneathTheMask: Not shown too much in the series, but in an interview Craig Bartlett said she had a hidden dark side. However, this calls for a reevaluation of pretty much all her scenes involving Arnold and his unreciprocated crush on her. Her dark side may have very well been there, just hidden under a veil of passive-aggressive sweetness.
* BettyAndVeronica: The Betty to Helga's Veronica for Arnold's Archie.
* BlondeBrunetteRedhead: The Redhead to Helga's Blonde and Phoebe's Brunette.
* BewareTheNiceOnes: It's made pretty clear by WordOfGod that she does have a dark side, though it's been hidden during the show's run.
* TheChick
* ChromaticArrangement: Green to Helga's Pink and Phoebe's Blue.
* CountryMouse
* DudeMagnet: She's popular with the boys.
* {{Foil}}: To Helga, big time. A great deal of Lila's appearances, and the nature of Arnold's relationship with both, play up how Lila is everything Helga isn't.
** [[WordOfGod according to Craig]] Lila had a repressed dark side. So in addition, while Lila was sweet and innocent on the outside, but emotionally disturbed on the inside, Helga was mean and crazy on the outside, but kind and sophisticated on the inside.
* GirlishPigtails
* HeroesWantRedheads
* LoveRevelationEpiphany: In "Arnold Loves Lila", Lila starts to like Arnold only because Helga wrote "Arnold Loves Lila" on the wall and Lila assumed it had to be true. Arnold tells her he doesn't "LIKE-like her" and Lila becomes very disappointed, but realizes she only came to "LIKE-like" Arnold because she thought he felt that way about her. So when Arnold realizes he does "LIKE-like her", Lila isn't interested in him anymore.
* ManipulativeBitch: Not to an extreme, but there are times when, looking closely, you see Lila's rather sly. In a subtle way by expressions and choice of words. There's the question of her and Arnold's interactions, plus the fact that she reeled Helga in with no choice but to confess her secret rather impressively in "School Play". With Craig's claims of her having a locked dark side, it makes one wonder.
** When asked about Helga and Lila becoming friends in the future (and if that meant that Helga accepts Olga as well) in The Arun Mehta Show Special With Craig Bartlett, which confirmed the idea was more of [[{{Fanon}} fan canon]] rather than actual canon that he's thought of, he had this to say -
-->'''Craig''': Helga and Lila have a really complex relationship because Lila has helped her keep her secret and helpe--and Lila's a bit of a player, you know, she kind of manipulates people in her--in her sort of innocent way.
* MasterOfTheMixedMessage: Offers a sort of unintentional hope spot for Arnold sometimes, but ends up emphasizing at the end that she does not "like him ''like'' him"
* NiceGirl
* ParodySue
* ThePollyanna
* RedheadInGreen
* SecretKeeper: Due to events in "School Play," Helga is forced to confide in her that she loves Arnold. (Naturally, before telling Lila, Helga threatened to strangle her if she ever told anyone.)
* ShipperOnDeck: Ironically, if mildly. She thinks Helga's crush on Arnold is "ever so sweet" and is more than willing to bow out of the way so Helga can orchestrate a kiss with him.
* StepfordSmiler: Implied, according to WordOfGod.
* TomboyAndGirlyGirl: Girly Girl to Helga's Tomboy.
* TownGirls: The Femme to Helga's Butch and Phoebe's Neither.
* UnrequitedLoveSwitcheroo: In "Arnold Loves Lila", when Lila believes Arnold has a crush on her, she starts to like him too, but he "likes her, but doesn't LIKE-like her". Once she gets the message, he really does start to "LIKE-like her". Unfortunately, Lila decides that she now just likes him and insists in being JustFriends for the rest of the series.
* VerbalTic: "Ever so", "oh so", and "I'm certain that..."
* WhatDoesSheSeeInHim: For some reason, she goes completely head over heels for Arnold's cousin Arnie.
* YouthfulFreckles

!! Thaddeus "Curly" Gammelthorpe
-> Voiced by: Adam Wylie; Steven Hartman ("Downtown as Fruits"); Haley Joel Osment ("Deconstructing Arnold"); Michael Welch ("Curly's Girl" and "Ghost Bride")

Psychotic kid with black hair and glasses

* AbhorrentAdmirer: To Rhonda.
* AxCrazy
* BewareTheQuietOnes: In "Curly Snaps". It was even lampshaded by Helga:
--> '''Mr. Simmons:''' I think we've all learned a valuable lesson here today.
--> '''Helga:''' Yep. Don't ever trust the quiet ones. They'll go bonkers and hole up the principal's office.
* CreepyChild
* DoesThisRemindYouOfAnything: In "Curly Snaps", he, well, [[ExactlyWhatItSaysOnTheTin snaps]], locks himself in the principal's office and throws basketballs at all his classmates who he thinks mistreated him for years. The other pupils react very shocked that the quiet Curly is capable of this.
* DisproportionateRetribution
* EmbarrassingFirstName: "Thaddeus."
* EvilLaugh
* ForcefulKiss: Just ''loves'' giving these to Rhonda.
* JerkAss: Probably the biggest out of all the kids, which is saying something.
* LargeHam
* LaughingMad
* TroublingUnchildlikeBehavior: Curly is consistently portrayed as criminally insane.
* StalkerWithACrush: To Rhonda.

!! Eugene Horowitz
-> Voiced by: Christopher J. Castile (early season 1); Jarrett Lennon (later season 1); BenDiskin (seasons 2, 3, and 4); Blake [=McIver=] Ewing (season 5 and TheMovie)

An extremely unlucky kid.

* {{Adorkable}}
* AmbiguouslyGay: His bedroom is [[TastesLikeDiabetes decorated with rainbows and unicorns]] and he seems to enjoy dancing and musicals.
** He also reacts with horror that he has to kiss a girl in "Romeo & Juliet". (The other boys do too, but Eugene specifically states, "I'd rather not kiss a girl." while the others just laugh.)
** Also, this dialogue from "Ghost Bride":
-->'''Sid''': ''(to Curly)'' I can't believe you pulled such a dirty trick on us!
-->'''Eugene''': ''(to Curly)'' I can't believe how nice you look in that dress.
* AmbiguouslyJewish
* BornUnlucky: He was also born on a Friday the 13th.
* ButtMonkey
* CatchPhrase: "I'm okay", said after something bad happens to him.
* TheChewToy
* IronicName: His name means [[BornLucky "born lucky"]].
* TheJinx: The other kids think he is one of these, and Arnold often gets dragged into trouble when he tries to help Eugene or prove that he ''isn't'' a jinx.
** After a while Eugene realises that some of his worse bad luck incidents (such as his bike being destroyed and his goldfish getting killed) happened when he was around Arnold, [[{{Irony}} prompting him to believe that]] ''[[{{Irony}} Arnold]]'' [[{{Irony}} is the jinx]].
* TheKlutz
* NiceGuy
* ThePollyanna: He is almost always freakishly happy and optimistic, despite his luck issues.
* ThrowTheDogABone: Arnold often tries to invoke this, but each time life tends to [[YankTheDogsChain yank the chain]].
* WideEyedIdealist
* YouthfulFreckles

!! Brainy
-> Voiced by: Craig Bartlett

An otherwise taciturn mouth-breathing nerd who seems to have a thing for Helga.

* AbhorrentAdmirer: To Helga.
* AuthorAvatar: WordOfGod has confirmed Brainy is his voice's actor ''other self''
* BeneathTheMask: Brainy knows who Helga truly is.
* CannotSpitItOut: Literally, the VaderBreath asthma never let say anything more than "Hi Helga" before the OffhandBackhand.
* {{Determinator}}: Nothing can dissuade him to be near to Helga.
* HiddenDepths: As confirmed by [[AllThereInTheManual The book six of the series Hey Arnold!]] [[http://www.amazon.com/Arnold-Arnolds-Files-Groening-Bartlett/dp/0439381495/ref=pd_sim_b_3 Arnold's E-Files]] Brainy is as eloquent as Helga… only that he cannot talk because his VaderBreath. Also, he is pretty good manipulating Arnold, loves poetry and is allergic to cats.
* InterruptedDeclarationOfLove: It's implied this is what Brainy is trying to say to Helga before [[RunningGag the usual]] OffhandBackhand.
* IWantMyBelovedToBeHappy: WordOfGod says this is how Brainy ultimately feels about Helga.
* OffscreenTeleportation: Being offscreen most of the time, it's pretty easy for Brainy to do this. Lampshaded in several episodes where he shows up behind Helga in the most ''improbable''. places, such as on Elk Island, the [[spoiler:Supposedly]] haunted train, and even in an Alley that Helga ''made sure'' was empty.
* OnlyKnownByTheirNickname
* TheQuietOne
* RejectionAffection: While Helga is busy being a StalkerWithACrush to Arnold, Brainy is doing the same to Helga, but a lot more openly. No matter how many times she hits him, he persists.
* SatelliteCharacter: To Helga.
* ScaryFlashlightFace: In the opening theme, complete with an offscreen scream as he does it
* StalkerWithACrush: To Helga.
* ShadowArchetype: Helga is an {{Hypocrite}} with HiddenDepths who denies her feelings. Brainy is a guy with HiddenDepths who always try to say her feelings (but cannot for the asthma). [[BeYourself Brainy is the one thing Helga wants and fears to be]]. Brainy is Helga's SatelliteCharacter [[FridgeBrilliance because Brainy is Helga's self, and Helga is Brainy's]] ShadowArchetype.
* VaderBreath

!! Sheena
-> Voiced by: Francesca Marie Smith

* AbhorrentAdmirer: She's good friends with Eugene, but while she's happy about Rhonda's marriage prediction in the episode "Married", Eugene's response is...less than enthusiastic.
* FragileFlower: Helga manages to convince her to drop out of Romeo and Juliet when she tells Sheena how bloody and sad the play really is.
* GranolaGirl
* HugeSchoolgirl: Easily the tallest girl in class; towers over many of the ''adult'' characters at only nine years old.
* SatelliteCharacter

!! Ruth P. [=McDougal=]
-> Voiced by: Lacey Chabert; Anndi L. [=McAfee=]

* TheDitz: She thinks Arnold's secret note to her is from a famous poet, Anonymous.
* HeroesWantRedheads: Her auburn hair is explicitly mentioned in "What's Opera, Arnold."
* SatelliteLoveInterest: Her only role in the show is to be Arnold's crush early on. Effectively disappears after Arnold finds out that they have nothing in common.

!! Patricia "Patty"/"Big Patty" Smith
[[quoteright:200:http://static.tvtropes.org/pmwiki/pub/images/pattysmile_5535.jpg]]
-> Voiced by: Creator/DanielleJudovits

* BigOlUnibrow
* DullSurprise: How she speaks. All the time. Which contrasts Harold who is very dramatic and hammy.
* HiddenDepths: Underneath that tough championship arm wrestler outer shell is a polite girl who volunteers at homeless shelters and knits.
* HugeSchoolgirl: Her parents look like midgets next to her.
* InSeriesNickname: Overlaps with EmbarrassingNickname. Most kids call her "Big Patty" even though as Harold says, ''"Her name isn't Big Patty, it's Patty!"'' Once people get to know and respect her, they drop the "Big."
* NoGuyWantsAnAmazon: Played with. [[JerkAss Sid and Stinky]] mock Patty because of her size, saying if they had to dance with someone like her, she'd probably crush them. But Harold, no small fry himself, likes Patty, not because he's an AmazonChaser but because they have a genuine connection, one that leads to them spending all night just talking.
* ProperLady: Shockingly yes, if she would stop beating kids up. Then again she apparently only goes after people who have provoked her.
* SecretKeeper: Implied- In "Helga vs. Patty", she makes an offhanded comment about Helga seeming fond of Arnold. [[{{Tsundere}} When Helga angrily denies it]], Patty just smiles knowingly.
* TomboyWithAGirlyStreak
* TrueBlueFemininity

[[/folder]]

[[folder:The Adults]]

!! Olga Pataki

[[quoteright:231:http://static.tvtropes.org/pmwiki/pub/images/54802_148091_1783.jpg]]

-> Voiced by: Nika Futterman

Helga's older sister and the parental favorite, much to Helga's dismay (and Olga's too, as revealed in "Olga Comes Home"). At first glance, Olga appears perhaps too perfect: Successful, pretty, smart, and sweet and kind to everyone. But she's actually dangerously neurotic, melodramatic and out of reality, due to having to constantly live up to her parents' (well, her father's, anyway) constant attention and ridiculously high standards.

* AloofBigSister: Unintentionally she is this to Helga.
* AwLookTheyReallyDoLoveEachOther: With Helga in every single episode she appears in.
* BareYourMidriff
* TheBGrade: Hasn't received an A- since third grade. In the "Olga Comes Home" episode, she cried for days in bed because she saw a B+ on her report card. Turns out, it was Helga who intercepted her college report card and changed her grade out of jealousy.
* BrokenAce: She seems to be perfect at everything, but underneath her [[StepfordSmiler façade]] she's incredibly broken due to her father's absurdly high standards for her.
* CoolBigSis: In the aptly-named episode "Big Sis", she becomes one to Lila through volunteer work. With her biological sister Helga, however...not so much, but only because Helga can't stand her. However, Olga's come through for Helga on several occasions.
** Averted in the episode where Olga becomes a teacher's assistant- she proceeds to tell ''the whole class'' that Helga used to wet the bed, [[WhatTheHellHero then gives Helga a detention when she lashes out at all the teasing that follows.]]
* EmbarrassingNickname: To Helga- she insists on calling her "Baby Sister".
* ExtremeDoormat
* FriendToAllChildren: Regardless of what Helga thinks, her schoolmates love Olga.
* NervousWreck: Underneath her [[PuritySue "perfect girl"]] [[StepfordSmiler façade]].
* NiceGirl
* ParentalFavoritism: On the good end of it, which turns out to [[DeconstructedTrope not be so good for her, in actuality]].
-->'''Olga:''' You must think I'm lucky, all the attention I get from them. I have to perform for them all the time like some kind of wind-up doll. I get really sick of it. You're lucky they don't even notice you.
* ParodySue
* ThePerfectionist
* SexySchoolwoman
* StepfordSmiler: Type A.
* UnknownRival: She genuinely has no idea Helga has been competing with Olga her whole life, and seems genuinely ''shocked'' when Helga tells Olga she can't stand her.
* ZettaiRyouiki

!! "Big" Bob Pataki

[[quoteright:239:http://static.tvtropes.org/pmwiki/pub/images/tumblr_liyq0b3ktB1qfd7xg_2931.jpg]]

-> Voiced by: MauriceLaMarche

Father of Helga and Olga. Runs a local business aptly named "Big Bob's Beepers".

* AbusiveDad: Emotionally to both daughters, but in completely different ways.
* AccidentalMisnaming: Consistently calls Helga by her sister's name, and almost always gets Arnold's name wrong.
* BigOlUnibrow
* DependingOnTheWriter: Abusive {{jerkass}} or simply an ignorant boor who just doesn't understand how much trouble he's caused for his family?
** CharacterizationMarchesOn: The latter characterization became steadily more common from Season 2 and onward. In the first season, he was portrayed as pretty much devoid of redeeming qualities.
* TheDragon: To Scheck in the movie, in order to build a bigger Big Bob's Beepers. [[spoiler:Though he defects from Scheck once he finds out that he's getting only 49% of the income.]]
* [[EducationMama Education Papa]]: Most of the pushing towards excellence that Olga received came from Bob's end, as he was the one who made it a big deal that she win so many awards and trophies, while Miriam just provided commentary. In the early seasons he even tried to shape Helga into following Olga's path.
* FatBastard: Most of the time.
* {{Gasshole}}: He belches and breaks wind on occasion.
* GoshDangItToHeck: Tends to say "Mother Hubbard" and "Heck".
* HumiliationConga: Helga was so disturbed by the "Orphan boy" line (see below) that during a gladiator-style event, she told Phil what Big Bob's weakspot was. Basically, she told him to go for the ankles, which sent Big Bob into a tub of gelatin - costing him the event and the overall win.
** Basically any episode that accentuates his JerkAss qualities ends with him getting a solid block of hilarious karma dropped on his head. "Roughin' It" is another good example, where he ends up alone in his RV stuck with sunburn, swamped with bugs, and itching from poison ivy (not to mention having been electrocuted by his own faulty products earlier) while everyone else enjoys camping the old fashioned way.
** He goes through another in "Summer Love". He sits in a lounge chair, gets sunburned, and has no one to take care of him, not even his wife whom he neglects. When he tries getting out of the house, he irritates his sunburn and gets a defeating blow from Miriam.
* {{Jerkass}}: Most of the time, he's this.
** JerkWithAHeartOfGold: While he rarely shows it, he does love and care about Helga, and in some instances can help out other characters when needed. They even hint that he does care about his wife as well, especially in "Summer Love" when she told him about another man teaching her "the Watoosty".
* KickTheDog: His "orphan boy" line (referring to Arnold) in "Parent's Day". It's so mean it would be a Moral Event Horizon if he'd said it directly to Arnold (as it stands, he was talking to Helga and was just characteristically loud and uncaring about anyone else overhearing).
* MyGodWhatHaveIDone: In the HalloweenEpisode he was legitimately horrified when he realized he just attempted to murder Helga [[ItMakesSenseInContext thinking she was an alien]], calling himself a monster.
* ParentalFavoritism: To Olga.
* ParentalNeglect: To Helga.
* TookALevelInKindness: "Big Bob's Crisis" was all about Bob realizing his high-stress life made him obnoxious, cruel and abusive to those around him - though he initially overcompensates by uprooting the entire family and becoming an ExtremeDoormat, it ends with him deciding that he can be his old self while still being a little kinder and a little less stressed. Since this was his last appearance in the show, it's unknown whether or not he would've kept at it.
* WouldntHurtAChild: He may be a {{Jerkass}} like his daughter and use verbal abuse, but Bob draws the line when it comes to physically harming a child. In the Halloween episode he almost had Helga killed when he thought she was an alien, until he learns that "alien invasion" was just her in costume for a theme - at which point he was ''very'' distraught.
* WhyCouldntYouBeDifferent: To Helga.
** [[LikeFatherLikeSon Like Father, Like Daughter]]: On the other hand, him and Helga are very similar in many aspects.

!! Miriam Pataki

[[quoteright:210:http://static.tvtropes.org/pmwiki/pub/images/char_54257_1333.jpg]]

-> Voiced by: KathSoucie

Mother of Helga and Olga, Miriam is a depressed, constantly sleepy, seemingly ditzy housewife with an addiction to "smoothies" (WordOfGod confirms that all of these are signs that Miriam is an alcoholic, with "smoothies" as a cover-up for booze). It's not uncommon to find her sleeping in strange places. However, she can be very competent and intelligent, but unfortunately it seems that being married to Big Bob has really brought her down.

* AlcoholicParent: While they couldn't state it outright (since ''Hey Arnold'' is still a kids' show, despite the myriad of "adult jokes"), Miriam is obviously a heavy drinker, with the show using smoothies as a metaphor for booze. If you look closely when she grabs some ingredients for her "smoothies", she grabs a bottle of Tabasco sauce and if "The Pataki's" was made, it is informed she would be attending AA.
* TheDitz
** TheAlcoholic
* AllGirlsLikePonies: In "Road Trip," she reveals to Helga that when she was a kid, she wanted to learn to ride horses, but her dad refused to let her, fearing she'd get hurt. Her response to this, surprisingly enough, was to [[spoiler: become a champion mechanical bull-rider.]]
* DrivesLikeCrazy: Due to her drinking, Miriam has had her license revoked. When she took over for Bob's beeper store and drove Helga to school, all the kids were worried that Miriam was driving again (meaning that the kids know that Helga's mom is either a DrunkDriver or just a very, very bad driver).
* HiddenDepths: She was once a world-class swimmer, won a bull-riding competition as a girl, and can run the family business better than Bob can if she wanted to.
* HypocriticalHumor: Calls Helga 'weird' in one episode when she hears Helga manically laughing in her StalkerShrine.
* INeedAFreakingDrink: She'll occasionally say that she needs a "smoothie".
* {{Meganekko}}
* MyGodWhatHaveIDone: In 'The Beeper Queen', when she realises she's been neglecting Helga for her new job.
* OddFriendship: Develops one with Suzie in "The Summer House".
* VerbalTic: Often speaks in a slow, drawling voice. Justified as Craig Bartlett has revealed that Miriam is an alcoholic.

!! "Steely Phil" [[spoiler:Shortman]]
-> Voiced by: Creator/DanCastellaneta

Arnold's grandfather.

* AnnoyingYoungerSibling: He acts like this to his older twin sister when she comes over to visit. This lowers after Arnold helps him and Mitzi make peace.
* BadassGrandpa
* BelligerentSexualTension: With Gertie when they were younger.
* CassandraTruth: In "Girl Trouble," he flat-out tells Arnold that Helga constantly teases him because she likes him. Arnold naturally doesn't believe him.
* CloudCuckoolander: Not to the extent of his wife, but some episodes play this up to the hilt, such as the one where he believed himself stranded on a deserted island and confused a flock of ducks for his ancestors.
* CoolOldGuy
* GenerationXerox: "Girl Trouble" reveals Phil was teased by Gertie the same way that Arnold is teased by Helga.
* GenreSavvy[=/=]MetaGuy: He often describes the plot templates in play.
* GettingCrapPastTheRadar: At least half the instances of it in this show come from him. Chief among them being that he's named after a type of dildo.
* NoodleIncident: Phil was apparently an acrobat in a Russian circus.
* ObfuscatingStupidity: Uses this on occasion, most notably in a flashback to his days in WorldWarTwo where he tricks group of Germans who had captured him into eating spoiled meat.
-->"It was then I realized that if I let the Major think he was smarter than me I could make him do anything I wanted..."

!! Grandma Gertie (aka Pookie)
-> Voiced by: TressMacNeille

Arnold's grandmother.

* AffectionateNickname: Pookie
* BelligerentSexualTension: With Phil in her youth.
* CloudCuckoolander
* CoolOldLady
* GenerationXerox: In "Girl Trouble," she and Phil had a relationship very similar to Helga and Arnold when they were younger. As part of the gag, Gertie in the flashback is voiced by Helga's voice actor.
* GirlishPigtails: In her youth.
* LetsGetDangerous: She saves the day when even Arnold fails. For example repairing the underground or stopping Bob's bulldozer.
* LovingBully: In her youth.
* NeverMessWithGranny
* ObfuscatingInsanity: There are rare times where she behaves in an odd fashion - only to then imply it was just an act.
* OnlyKnownByTheirNickname: Usually referred to as "Grandma," "Pookie" or other nicknames. Her first name is mentioned as part of the GenerationXerox twist in "Girl Trouble."
* OOCIsSeriousBusiness: In "Parents Day," she acts like her usual fun-loving, crazy self. After seeing Arnold so depressed over his ParentalAbandonment, however, she snaps out of the role she was playing and acts far more subdued.
** Played for laughs during a heat wave; Arnold notes that the heat's ''so'' bad that even his grandmother is acting normal. [[spoiler:Her wearing scuba gear and walking around like she does it every day when it starts raining is a sign that everything is going to be fine]].
* {{Tsundere}}: In her youth.

!! Mr. Simmons
-> Voiced by: Dan Butler

Fourth grade teacher at P.S. 118 starting in the second season, replacing the original LivingProp, Miss Slovak. Thinks of everyone and everything as "special".

* AdultsAreUseless: Specifically in the episode "Girl Trouble" when he doesn't punish Helga for bullying Arnold, yet he punishes ''Arnold'' for fighting back. Other examples include:
** "Buses, Bikes, and Subways"--doesn't double-check his head count and is totally oblivious to the fact that two of his students are missing until the bus is back home.
** "The Flood"--allows students to run riot for 3/4 of the episode and then tries to [[spoiler: climb up a ladder during the storm for help, and ends up falling into several feet of water, meaning the kids have to save his butt.]]
** "Aptitude Test"--mixes up two of the eponymous tests; doesn't bother to recheck the folders.
** "On the Lam"--doesn't know his science closet was raided until informed on evening news.
* AmbiguouslyGay: Played by an openly gay actor, loves the theater, and has a very delicate, effete personality. In fact, a character who may or may not be his partner even appears in [[CrappyHolidays the Thanksgiving episode]].
** Confirmed by WordOfGay.
* CoolTeacher: He can be this when he's not being useless. In fact, his premiere episode, "New Teacher," was all about the kids realizing this after they gave him a hard time.
* ImagineSpot: In "Principal Simmons", Mr. Simmons imagines what the school would be like if he was the principal, which features the kids all beings friends with each other, Helga and Brainy walking together with their arms around each other, Wolfgang giving Eugene a piggyback ride, Harold becoming smart, the kids eating healthy food and happy to be the principal's helper.
* InkSuitActor: A very glaring example on a show with otherwise very outlandish character designs; Simmons strongly resembles his voice actor, Dan Butler.
* NiceGuy: One of the nicest adults in the series.
* NonStandardCharacterDesign: Considerably less cartoony-looking than the other characters due to being based on a real person.
* ObliviousToHisOwnDescription: He is the only one who doesn't recognize his own CatchPhrase in Helga's parody.
* OnlyOneName: It is strongly implied, but never explicitly stated, that his first name is Robert (in the Thanksgiving episode, he wrote a play that was based on his own life; we meet every character from the play in person later on except for him).
* WideEyedIdealist

!! Alphonse Perrier du von Scheck
-> Voiced by: Paul Sorvino

The CEO of Future Tech Industries, Scheck is a greedy and heartless businessman who wants to tear down Arnold's neighborhood to build a gigantic, immaculate shopping mall. Only appears in TheMovie, where he is the BigBad.

* AffablyEvil: Appears to be this at first, but it fades over the course of the movie.
* BigNo: After he sees that [[spoiler: Arnold, Helga and Gerald have escaped - with the videotape that exposes him burning the document]].
* CorruptCorporateExecutive: Not only is he not above [[spoiler: burning a document declaring the neighborhood a national landmark]], the whole reason he wants to build the mall in the first place is to [[spoiler: get revenge after his family name was sullied over the "Tomato Incident" that happened in front of Sunset Arms]].
* EvilOverlooker: On the poster and DVD cover of TheMovie.
* GreenEyes
* ManOfWealthAndTaste: A small running gag has Gerald voice admiration for Scheck's suit.
* SlasherSmile: Most notably when he's [[spoiler: burning the document declaring the neighborhood a national landmark]].
* SmugSnake
* SoftSpokenSadist: His voice is pretty unassuming and even somewhat soothing for a villain, but he tends to lose this when he gets mad.
* VillainousBreakdown: He starts out appearing as an affable but very weaselly businessman, but ends up as a raving madman who is [[MoralEventHorizon perfectly willing to]] [[spoiler: run over several people, including children, with his car.]]
* TheVonTropeFamily

!! Bridget
-> Voiced by: Jennifer Jason Leigh

Only appearing in TheMovie, Bridget is a sort of spy girl/superheroine who helps Arnold and Gerald save the neighborhood by supplying them with equipment and [[spoiler:providing them a VCR to play the security tape exposing Scheck]].

* MsFanservice: Both Arnold and Gerald immediately fall for her as soon as they meet her, and Gerald even faints when she gives him a good luck kiss.
* SpyCatsuit

!! Oskar Kokoshka
--> Voiced By: Steve Viksten

* AnnoyingLaugh: Eh heh heh heh!
* ButtMonkey: He largely deserves it, too.
* FunnyForeigner: Mentioned in one episode as hailing from the former Czechslovakia.
* {{Jerkass}}
** JerkWithAHeartOfGold: Most notably the episode where he's forced to look after Baby Oscar, whom he initially resents but grows protective over, and when he feels guilty about leeching off Suzie.
* LazyBum and LazyHusband: Lives off his wife ''and'' still expects her to do all the housework.
** When he finally does get a job delivering papers with Arnold's help, he's too lazy to even do that, making up excuses so that Arnold does it instead of him. It gets to the point that ''even [[NiceGuy Arnold]] calls him a big loser.''
* ManChild
* UglyGuyHotWife

!! Suzie Kokoshka
--> Voiced By: Mary Scheer

* [[HenpeckedHusband Henpecked Wife]]: Though female, Suzie is the sole source of income, and is run ragged by her childish husband.
* NoAccountingForTaste: Although she fights with Oskar often and has kicked him out on more than one occasion, she always seems to forgive him, only to have him make the same mistakes again.
* OddFriendship: With Miriam in "The Summer House".
* ParentingTheHusband
* UglyGuyHotWife

!! Ernie Potts
--> Voiced By: Dom Irrera

* BigOlUnibrow
* FieryRedhead: Male example, although he is mostly bald.
* FirstNameBasis: Unlike most of the other boarders, Arnold calls him Ernie in later seasons, although he does call him Mr. Potts early on.
* HotBlooded
* TheNapoleon: Shorter than Arnold, but very passionate about the demolition business.
* TinyGuyHugeGirl: He develops a crush on a very tall model named Lola, and the two even date [[spoiler:until they had a falling out due to Lola being uncomfortable with their difference in height, though she apologizes, and they remain friends at the end of the episode.]]

!! Mr. Hyunh
--> Voiced By: Baoan Coleman, Music/RandyTravis (singing)

* CharacterizationMarchesOn: Mr. Hyunh is initially a stereotypical, high-tense Asian man who mostly panic and tends to yell the same thing over and over whenever there's trouble. Early into the show, this aspect of his character is lessened as they make him into more of a character and less of a stereotype.
* FunnyForeigner
* HiddenDepths:
** Though he comes off as a somewhat overdramatic FunnyForeigner in most episodes, some (in particular the ChristmasEpisode) where he has ADayInTheLimelight, show him to be more insecure and worried about his situation.
** There's also the episode where it's revealed he sings ''amazingly'' as a country artist. So much that Gerald was able to profit out of him for the episode before Hyunh chose "The Simple Things" of his life instead of the limelight.
* LargeHam: How he responds to frustrating situations.
---> '''Mr. Hyunh:''' This lint. ''Your lint''! I cannot keep cleaning up after you! I am ''not your mother''! ({{beat}}) ''I'm not his mother!''
** And the time he dressed up as Juliet in order to help Romeo Arnold learn his lines in "School Play".
* LastNameBasis: Even the ''adults'' at the Sunset Arms call him Mr. Hyunh.
* OnlyOneName: See LastNameBasis above.

!! Miles and Stella [[spoiler:Shortman]]

[[quoteright:350:http://static.tvtropes.org/pmwiki/pub/images/miles_stella_arnold_4802.png]]

-->Voiced by: Craig Bartlett (show creator) and Antoinette Stella (an episode writer)

Arnold's long missing parents.

* [[AdventurerArchaeologist Adventurer Anthropologist and Botanist Doctor]]: Perhaps to make them not be exactly like Indiana Jones they aren't Archaeologists, but have other jobs that would mean they might spend most of their time in a South American rainforest. But they still manage to rescue an artifact from a Jungle Pirate anyway.
* BattleCouple: If Phil's stories and Miles' journal is to believed.
* BirdsOfAFeather
* HappilyMarried
* [[DaddyHadAGoodReasonForAbandoningYou Mommy & Daddy Had A Good Reason for Abandoning You]]: [[spoiler:They both left to help cure a deadly illness sweeping throughout the population of the South American country, particularly that of a secretive tribespeople who have helped them throughout the years who they owe their lives to.]] As Miles had written in his journal he expected the trip to be a short one... [[spoiler:it is possible they too died of the illness in the end, though there is a HopeSpot when Arnold finds a map of their trail.]]
* ParentalAbandonment: Both left Arnold to be looked after by his Grandparents to depart on an important mission.
* ScreamingBirth: To give Stella her dues she may be angry at the time, but she manages to keep it together rather well for a woman [[spoiler:giving birth in remote Jungle Temple whilst a ''volcano is erupting all around her!'']]
* WhipItGood: Miles is extremely proficient with a whip, using it to tether two cable-cars together at one point to stop one from falling.
!!Principal Wartz:
As you guess, he's the principal of P.S. 118 and he's known to be harsh but has reasons to be one. Throughout the show, Wartz often is seen taken punishments too far, even by following teachers but he has toned this down after realizing when he sees how the others handle order.

* JerkAss: Pretty much defines this.
* ManChild: Shown to be this as he is seen playing with toys at his work desk and sending fan mail to teen singing sensation, Ronnie Matthews.
* PetTheDog: He can be reasoned with, even letting a kid off the hook depending on the situation.
** He also has a set of toy animals on his desk in order to calm down and/or reduce the stress on any meeting he may have.
* ProperlyParanoid: Even if the kids have no interest in misbehaving, Wartz is often like this.
* SternTeacher: He’s harsh at times but he’s willing to negotiate if the situation can be resolved.
!!The Jolly Olly Man (Willie)
A mean, sadistic, downright crazy guy who works as an ice cream man.

* AesopAmnesia: Subverted. In ''Career Day'', Arnold teaches him how to properly do his job and avoid getting fired. In subsequent appearances he flip-flops from being the same jerkass he always was, and actually doing his job well.
** When Grandpa Phil accidentally runs him off the road in ''Grandpa's Packard'', he goes as far as to dress up in drag, and trick Phil into giving his address, so he can steal the Packard from him. He apologizes after he gets arrested, though.
** He makes a small appearance in the movie, though, where he seems to be good at his job again.
* {{CloudCuckooLander}}: He's apparently convinced in ''Grandpa's Packard'' that the start of his bad day was his dog laughing at him.
* EvilLaugh
* FreudianExcuse: In 'Career Day', Arnold finds out he's been fired from every single job he's had, and his BadBoss is none other than his ''own Dad'', who treats him with utter contempt.
* IronicNickname: The ''Jolly'' Olly Man.
* JerkAss: He'll drive off without giving kids their ice cream, not give them the right flavors, yell at them and treat them with no respect, or just outright ignore them.
* NeverMyFault/NoSocialSkills: He was not aware there was ''anything'' wrong with his attitude, and views the children he serves as frightening. When his boss/father shows up saying that his numbers are down, he says it's not his fault that kids these days don't want ice cream.
** There was also a moment in ''Grandpa's Packard'' where he says that he was having a terrible day, one of the reasons being that the expiration date on his milk was wrong. ''He's'' not wrong, ''the milk'' was wrong. It'd be somewhat believable if it wasn't preceded by his dog laughing at him, and followed by a maniacal Grandpa Phil running him off the road on purpose.
* PetTheDog: He gives Arnold an 'A' at the end of 'Career Day' and a free ice-cream, as thanks.
* SlasherSmile: Accidentally scares kids off with his smile when Arnold is trying to improve him.
* ThroughTheEyesOfMadness: We occasionally see how he views the world. In ''Career Day'', he sees the city in black and white and nothing but slums, the kids as hyperactive [[CreepyChild creepy children]], and his ice cream truck as a cage.
** ''Grandpa's Packard'' shows that he views Grandpa's running him off the road as a malicious act against him, and not a mistake, complete with an evil looking Packard spewing flames and Grandpa Phil laughing maniacally.

!!Pigeon Man:
--> Voiced by Vincent Schiavelli
An outcast who lives atop an abandoned apartment block who prefers to be around pigeons than humans.

* ButNowIMustGo
* LonersAreFreaks
* NotGoodWithPeople
* OneEpisodeWonder
* OnlyKnownByTheirNickname

[[/folder]]

[[folder:Other Kids]]

!! Arnie
-> Voiced by: Grant Hoover

A cousin of Arnold's who is disconcertingly similar, but much stranger and less attractive. Naturally, Lila falls head over heels for him.

* AmbiguousDisorder: Arnie displays several signs of ASD, particularly AspergersSyndrome, such as odd hobbies (counting things, reading ingredient labels [along with seemingly knowing what they are and how to pronounce them]) and collections (specifically balls of lint and "plain flavored" gum), displays muted outward signs of emotion, and seems to have difficulty in social interaction. These traits lead some of the other characters to think he is "dull" and "slow."
* BizarroUniverse: The episode "Arnold Visits Arnie", in which just about all of the side character kids and main cast members get an eerily similar doppelganger with a completely opposite personality.
* CountryCousin
* CreepyMonotone: Though the "creepy" is entirely up to the viewer's discretion.
* JokeCharacter: Reportedly a character created as an in-joke response to OffModel animation.
* [[KavorkaMan Kavorka Kid]]: Big time.
* MirrorUniverse: In "Arnold Visits Arnie", to some degree. That is, of course, if you [[spoiler: believe that it isn't normal for Arnie to go AxeCrazy on his cousin and/or]] want to include the character alignments of the citizens of Arnie's hometown.
* [[spoiler: MurderTheHypotenuse: In "Arnold Visits Arnie" towards the end of the episode. It turns out it was just a dream, though.]]
* [[spoiler: NightmareFace: Arnie gets one, also a result of the fiendish dream. Almost makes you wonder about Arnold a little...]]
* OddballDoppelganger: To Arnold.
* ReplacementLoveInterest: This may be the reason why Lila was attracted to Arnie. Since Helga told her that she likes Arnold, she has agreed to let Helga have a chance with Arnold. When she saw Arnie, though, she saw the resemblance in their faces and pursued him in place of his cousin.
* [[UglyGuyHotWife Ugly Guy, Hot Girlfriend]]: Arnie's less-than-attractive guy to Lila's, and later Lulu's [[spoiler: (though this turned out to be AllJustADream)]] rather pretty girl.

!!Rex Smythe-Higgins III:
--> Voiced by Joey Stinson
Rex Smythe-Higgins III is the grandson of Grandpa Phil’s rival Rex Smythe-Higgins I and is the same age as Arnold. He’s often had to complete against Arnold and is a Polishing school alumni.

* JerkWithAHeartOfGold: He may be arrogant at times, but he doesn’t like cheaters and rather play fair in completion, "Tour de Pond". In "The Pig War", he draws the line when eating pets.
* WiseBeyondTheirYears: He’s actually much more mature than his grandpa considering he’s still a kid.

!!Wolfgang:
--> Voiced by Toran Caudell
The leader of the fifth graders and bullies the fourth graders around.

* TheBully: Even worse than Harold and Helga.
* GeniusBruiser: He's surprisingly crafty, from devising plans for Trash Can Day to making sure Chocolate Boy doesn't eat chocolate for a month.
* HiddenDepths: He mentions that he needs to take oboe lessons until four.
* JerkAss
* JerkJock: Shows shades of this, especially "Longest Monday".
* KarmaHoudini: Most of the time, he and his fifth graders succeed without punishment.
* NotSoAboveItAll: He's very superstitious.
* YoungerThanTheyLook: It's hard to imagine that he's only fifth grade considering he has an appearance and a voice of a high school student.

!!Ludwig

Another bully introduced in 'New Bully On The Block', explaining he was at Juvenile prison and only recently got out.

* TheBully
* RealMenWearPink: He tells Arnold he has to go to his tap-dancing class when Arnold tries to arrange a meeting between him and Ludwig.
* RememberTheNewGuy: Averted- Arnold ''vaguely'' remembers Ludwig, but the show acknowledges he's never been seen before by explaining he went to Juvie before the series began.

[[/folder]]