!The Duncan Family (in order of billing):
!!Teddy Duncan (BridgitMendler)

A 15-year old high school sophomore and, until the new arrival, the middle child of the family. She records a series of video diaries for her baby sister for when she's older, which form a substantial portion of the show's narrative (and [[TitleDrop where the title comes from]]). She cares a great deal for her family, even if she isn't great at expressing her affection for some of them, and has a special attachment to her baby sister, Charlie. So far, she appears to be a good student, and is obsessed with most of the things typical of girls her age, preeminently boys.

* [[AloofBigBrother Aloof Big Sister]]: To Gabe.
* TheBGrade
* BigSisterInstinct
* CaptainsLog: Her video diaries.
* CatchPhrase: "Good luck, Charlie", though it's frequently [[BorrowedCatchphrase borrowed.]]
** [[LampshadeHanging Lampshaded]] in "Future Drama":
-->'''Future!Charlie:''' ''(after her attempt at following Teddy's advice has failed)'' I really have to watch these things to the very end. It's not over until she says...\\
'''Teddy:''' ''(on the computer screen)'' Good luck, Charlie.
* CoolBigSis: To Charlie and when not the [[AloofBigBrother Aloof Big Sister]], to Gabe.
* CuteClumsyGirl
* DeadpanSnarker
* DudeMagnet: She's well aware that many boys find her attractive. This becomes a plot point in several episodes, such as "Teddy Rebounds".
* FollowInMyFootsteps: Amy pushes Teddy to try to be the school mascot, purely because she was the mascot when she was a student.
** Amy also pushes Teddy to wear her old prom dress to Prom. Teddy then hides a prom dress in the bushes so she is able to wear a prom dress more fitting of her style.
* GenderBlenderName
* GenreSavvy
* GoGetterGirl: She's determined to get good grades, thinks getting a B is bad, and even joins the volleyball team to pad her college resume, even though she stinks at it.
* HairOfGoldHeartOfGold: In-universe, [[InformedAttribute she's considered to be this to a fault.]]
* InformedAttribute: Teddy being a goody two shoes [[DependingOnTheWriter in some episodes]].
* MsFanservice
* MysteriousMiddleInitial: Teddy's middle initial is R. It hasn't been stated what the R stands for.
* OfficialCouple: With Spencer, as of "Charlie Goes Viral", [[spoiler:and up until "Girl Bites Dog". Restarted in "Can You Keep a Secret?", up until "All Fall Down"]]
** [[spoiler:With Beau as of "Teddy's New Beau", until "Bob's Beau-Be-Gone".]]
* TheSouthpaw
* SpoiledSweet
* TomboyishName
* TheUglyGuysHotDaughter: Noted by Uncle Mel.
* WomenAreWiser

!!Amy Duncan (Leigh-Allyn Baker)

The 30-something mother of the Duncan family, who works as a nurse at a hospital. The main source of the show's humor and drama is the rest of the family's often-misguided attempts to help take care of the baby as Amy returns to work. She seems like the OnlySaneMan but her [[SmallNameBigEgo ego]] and SpotlightStealingSquad mentality keeps her from this.

* AdultsAreUseless: Averted.
* AttentionWhore
* BlondesAreEvil: Sometimes. It is also revealed that Gabe gets his evil/mischief traits from ''her''.
* {{Catchphrase}}: "Ba-Bam!"
* DeadpanSnarker
* FriendlyEnemy: Her relationship with Mary Lou, Ivy's mom.
** FriendlyRivalry
* {{Flanderization}}: Originally she played the role of OnlySaneWoman and just occasionally thought of herself as very good at something (like being her school mascot, even her coach agreed she was a great mascot), but by the end of Season 1 it turned into a case of SmallNameBigEgo.
* GenreSavvy
* HappilyMarried: To Bob
* HighSchoolSweethearts: With Bob.
* HospitalHottie
* HugeGuyTinyGirl: With Bob.
* JerkWithAHeartOfGold
* LethalChef: Heavily implied.
* MamaBear: Actually used by the Duncans to describe Amy - and [[JustifiedTrope she owns the trope]] ''[[RuleOfCool to very]] [[RuleOfFunny good effect]]''.
* MsFanservice: Even more so than her ''daughter''
* NeverMyFault
* OnlySaneWoman: Originally.
* ParentService
* SmallNameBigEgo: Amy likes to think that she's the best at everything she does, and seems to believe that she's a big time star just waiting to be discovered; she once replaced her family (except Charlie) with professionals for a group talent show, which she didn't technically apologize for.
* SpotlightStealingSquad: In-universe.
* TeamMom: Most notably in the episode "[[ExactlyWhatItSaysOnTheTin Team Mom]]."
* {{Tsundere}}
* UglyGuyHotWife

!!Gabriel P. "Gabe" Duncan (Bradley Steven Perry)

The sarcastic, often dour 10-year old son, who resents Charlie for having usurped his position as the baby of the family, and thus drawing a good deal of attention away from him. His perceptions seem somewhat justified. Continues the proud [[ThePartridgeFamily Danny Bonaduce]] tradition of looking ''nothing'' like the rest of the family.

* AloofBigBrother: To Charlie.
* AnnoyingYoungerSibling: To PJ and Teddy.
* BrilliantButLazy
* ButtMonkey
* DangerouslyGenreSavvy
* DeadpanSnarker
* TheEeyore
* EvilerThanThou: He and Mrs. Dabney are always on the banter about this.
* [[SheIsAllGrownUp He Is All Grown Up]]: As of the Season 4 premiere.
* {{Jerkass}}
** JerkWithAHeartOfGold: He has his moments.
* HollywoodGenetics
* MouthyKid
* MiddleChildSyndrome: Became like this after Toby's birth.
* MysteriousMiddleInitial: What does the P in Gabriel P. Duncan stand for again?
* ThePrankster
* TheSnarkKnight
* TallDarkAndSnarky: Gabe's shaping up to be this in Season 3.
* TheUnfavorite

!!Charlotte "Charlie" Duncan (Mia Talerico)

The 9-month old (as of the series premiere, currently 4 years old) newest addition to the Duncan family. She begins the series as an infant, not doing much except make noise, pooping and spitting up. Nonetheless, she's extremely cute, and quickly progresses to new milestones, such as making her first attempts at real English words, and taking her first steps. She is whom [[CharacterTitle the series' title comes from]].

* AnnoyingYoungerSibling: To some extent.
* AesopAmnesia: In ''Guys and Dolls'' Amy tried to help Charlie with her jealousy of Toby, which seemingly worked. Amy pretended to make Toby talk and say that Charlie is his favorite sister. Come ''Doppel Date'' however, Charlie wanted Toby to stay in the hotel. Justified she's a toddler.
* CharacterDevelopment: She gets a lot more characterization in seasons 3 and 4. As she grows up, she seems to take after Gabe, who was jealous of her, whereas now Charlie is jealous of Toby. She also appears to be shaping up to be a troublemaker, like Gabe. She's also inherited her [[SmallNameBigEgo mother's ego]] which has lead Amy and Bob to say she's her mother's daughter.
** In ''Duncan Dream House'', for the first time, Charlie was actually right about keeping their old home, and even had her own scene where she talks to her imaginary circle.
** If "Futuredrama" is any indication, she grows up to be more like Teddy.
* TheCutie
* [[EvilDetectingDog Evil Detecting Baby]]: In "Girl Bites Dog", Charlie bites Spencer because she somehow knows [[spoiler:he's cheating on Teddy.]]
* FromTheMouthsOfBabes
* GenderBlenderName
* GenreBlindness: Her future self learns this the hard way after getting beat up by 11-year old Toby, since she forgot to wait for the ending tagline of the video diary, "Good luck Charlie!"
* LittleMissSnarker: She's shaping up to be this in Season 3. This became evident when she picked up the phrase "aw nuts" from Amy.
* OnlyKnownByTheirNickname: Charlie's real name is Charlotte.
* PingPongNaivete: Charlie often appears really smart for a baby, but she'll be the SpannerInTheWorks if the plot calls for it.
* PlotDevice: However, thanks to CharacterDevelopment due to her growing up, there are some episodes where she gets a subplot of her own.
* ShesAllGrownUp: Her future self. The present Charlie even lampshades this during the CreditsGag of "Futuredrama".
* ShipperOnDeck: Implied to be this towards Teddy and Spencer.
* TomboyishName

!!Bob Duncan (Eric Allen Kramer)

The 40-something man of the house. Bob runs his own business as an exterminator. He seems rather absent-minded (not being able to recall Gabe's birthday or where he goes to school), and can be quite clumsy at times. He's also quite fond of his daughter Teddy, and can thus be overprotective of her.

* AdultsAreUseless: Sometimes averted.
* AndStarring
* BerserkButton: This cannot be stressed enough: Do '''not''' call Amy "crazy" or "a pest" in front of Bob. Yes Mr. Piper, we're talking to you.
* BigEater: Often becomes the butt of the jokes due to this.
* TheBigGuy
* BumblingDad
* TheConscience: Or at least when his wife goes off the deep end.
* DeadpanSnarker: Surprisingly often.
* DrivesLikeCrazy: Bob with the new car. First, he crashes it into the kitchen. Then, in the credits, he crashes it ''[[RuleOfFunny into the eight floor of a building]]''.
* FormerlyFat
* GenreSavvy
* HappilyMarried: To Amy
* HenpeckedHusband
* HighSchoolSweethearts: With Amy.
* HugeGuyTinyGirl: With Amy.
* InsistentTerminology: Prefers to be called a "pest-control specialist" rather than an "exterminator."
* IWasQuiteTheLooker: Looked like [[PrettyBoy PJ]] in his younger years.
* OverprotectiveDad: Bob towards Teddy.
* TheNoseKnows: Bob was able to identify the sex and species of a mouse, as well as the fact that it was pregnant, [[{{Squick}} by analyzing the scent of its droppings.]]
* UglyGuyHotWife

!!Potty John "PJ" Duncan (Jason Dolley)

The 17-year old eldest child of the family. He's a phenomenal airhead and a horrible student. His passion seems to be playing rock and roll, even though he's not very good at it. He cares a good deal about his family and wants earnestly to do his part in helping raise his baby sister, but his absentmindedness makes this difficult.

* AloofBigBrother: To Gabe.
* AndStarring
* {{Cloudcuckoolander}}
* CoolBigBro: To Charlie.
* TheDitz
** GeniusDitz: It's been stated and proven that he's the best cook in the house.
* DreadfulMusician: DependingOnTheWriter
* DeadpanSnarker: Has his moments, most notable in [[spoiler:Name That Baby.]]
* DumbassTeenageSon
* DumbBlonde
* GenreSavvy
* EmbarrassingFirstName: According to his birth certificate, PJ's name is revealed to be "Potty John". Bob tries to get it corrected, [[spoiler:but PJ's name is now "PP" Duncan.]]
* {{Expy}}: PJ is a grungier, working-class version of [[CoryInTheHouse Newt Livingston]]. This is made even more pronounced by the fact that the same actor plays both characters. PJ is probably smarter than Newt, but the characters on this show are smarter too, so it balances out.
** Older viewers might notice a few striking resemblances to [[FastTimesAtRidgemontHigh Jeff Spicoli]]. Take away the surfer accent, the BrilliantButLazy facets of Spicoli and the fact that Disney can't feature [[TheStoner the main trait that everyone remembers Spicoli for]], and you have PJ.
* FollowInMyFootsteps: Bob states that he'd like PJ to join him in pest control, and he'd rename the company to "Duncan & Son" if he did. PJ immediately decides to go study.
* KiddieKid: ''In spades''. The most visible example being how his favorite show is ''The Gurgles'', a ''Series/{{Teletubbies}}'' Expy starring singing, dancing shapes that even Charlie has outgrown.
* NiceGuy: Bob views PJ as the nicest of his children.
* ObfuscatingStupidity: Hinted at, as when he's focused, he's surprisingly on the ball. Mrs. Dabney even lampshades it: "Sometimes youre smart, sometimes you're dumb. Hard to keep up."
* OfficialCouple: With Skyler.
* OnlyKnownByTheirNickname: PJ is short for Patrick John. Actually, according to his birth certificate, it stands for Potty John.
* PrettyBoy
* UncannyFamilyResemblance: A video of Bob from his high school basketball days shows that he looked exactly like his son PJ does today, only with [[EightiesHair longer hair]].
* UnfortunateNames: PJ's name was supposed to be Patty John, after his grandfather, but the guy who wrote his birth certificate wrote "Potty John" instead. This is fixed by the end of the episode though. [[spoiler:But now it instead reads "PP".]]

!!Toby Wan Kenobi Duncan (not credited in main titles, played by Jake Cinoa & Logan Moreau)

The newest addition, he shares a birthday with Charlie.

* AudienceParticipation: The name and gender of the baby was determined by an online poll.
* PunnyName: His full name is T[[StarWars oby Wan Kenobi]] Duncan.

!Recurring Characters:

!!Ivy Wentz (Raven Goodwin)

Teddy's best friend. She hopes some of Teddy's popularity will rub off on her, and she thinks the Duncan family is incredibly strange but more entertaining than her own family. She's also a horrible student who rejoices over receiving her first B.

* AllWomenAreLustful
* BlackBestFriend: To Teddy.
* BookDumb: Ivy waited until her sophomore year in high school to get her highest grade ever: a B.
* DeadpanSnarker
* {{Expy}}: Ivy is clearly [[{{Glee}} Mercedes]].
* TheFashionista
* FatBestFriend
* SassyBlackWoman: [[DownplayedTrope Teenage version]].

!!Emmett (Micah Williams)

PJ's somewhat nerdy best friend, and the drummer in his band. He has an incredibly creepy crush on Teddy, which he's deluded himself into thinking is an actual relationship.

* BlackAndNerdy
* BlackBestFriend: To P.J.
* DreadfulMusician
* NiceHat: Is usually seen wearing one.
* StalkerWithACrush: Towards Teddy.

!!Mrs. Estelle Dabney (Patricia Belcher)

The Duncans' next-door neighbor. Mrs. Dabney is cranky, unfriendly, and at times, {{manipulative| bastard}}. Born in 1958 in Sheboygan, Wisconsin, she comes from a set of identical quintuplets, none of which are [[PolarOppositeTwins anything like her]] personality-wise.

* CardCarryingVillain
* TheComicallySerious
* DeadpanSnarker
* EvilRedhead
* {{Jerkass}}
* ManipulativeBitch
* MistakenForMurderer: PJ and Gabe misinterpret her outburst at her soap operas, and her attempts to get rid of the smell of death and a large, heavy trunk as evidence that she murdered her husband.
* [[PolarOppositeTwins Polar Opposite Quintuplets]]: Mrs. Dabney comes from a set of identical quintuplets, none of which are anything like her personality-wise.
* SassyBlackWoman: Averted. However, this begins to show in ''The Unusual Suspects'' when she says "You're not the boss of me!" to Amy.
* TheSnarkKnight
* UncannyFamilyResemblance: Mrs. Dabney apparently comes from a set of identical ''quintuplets''.
* WorthyOpponent: To Gabe.
* [[UsedToBeASweetKid Used To Be A Sweet Lady]]: According to Amy, Mrs. Dabney was much nicer before Gabe came around

!!Spencer Walsh (Shane Harper)

Teddy's study buddy, love interest, and eventual boyfriend (and then eventual EX-boyfriend). After numerous botched attempts, he finally gives Teddy her first kiss. He comes from a wealthy family, about which he's quite modest, and enjoys hip-hop dancing... oh, yeah, and he's a two-timing {{jerk|ass}}. [[spoiler:Teddy recently decided to give him a second chance and they're back together.]]

* CharacterDevelopment: Spencer started out looking like a SatelliteLoveInterest, but later turned out to be pretty interesting. [[spoiler:And then turns out to be a cheating {{Jerkass}}]]. To his credit, Spencer [[spoiler:deeply regretted his actions, and has made up with Teddy. They're dating once more.]]
* DidNotGetTheGirl: [[spoiler:Sadly, in ''Teddy's Choice'', he does not end up with her, this time through no fault of his own.]]
* DumbJock: At least from Victor's point of view.
* MistakenForCheating: {{Subverted}}. Teddy thinks Spencer is cheating on her with Skyler, but then learns from Spencer that she's his cousin. [[spoiler:He turns out to be lying. He ''is'' cheating on her with Skyler, who believes that Teddy is his cousin.]]
* MrFanservice
* MyGreatestFailure: [[spoiler:Cheating on Teddy]].
* OfficialCouple: With Teddy, as of "Charlie Goes Viral", [[spoiler:and up until "Girl Bites Dog". Restarted in "Can You Keep a Secret?"]]
* YourCheatingHeart: Turns out Spencer was using the "cousin" excuse to keep Teddy and Skyler from finding out about each other. Doesn't end well for him. For Spencer, [[spoiler:this has since become [[MyGreatestFailure his greatest regret]], and it takes a whole season for him to eventually gains Teddy trust while she begins to remember what he meant to her before she fully forgives him enough to take him back]].

!!Jo Keener (G. Hannelius)

A female student in one of Gabe's classes, she constantly threatens and bullies him. It turns out a part of her motivation is being unable to express her crush on him. [[ChuckCunninghamSyndrome Not likely to be seen again]] since the actress has moved onto other projects, namely ''DogWithABlog'' on the same network.

* TheBully: To Gabe.
** LovingBully
* CuteBruiser
* GamerChick
* GenderBlenderName
* TheLadette
* LittleMissBadass
* LittleMissSnarker
* PintsizedPowerhouse: She breaks Gabe's arm and Teddy's collar bone.
* SheCleansUpNicely
* TheSnarkKnight
* TomboyishName
* {{Tsundere}}

!!Skyler (SamanthaBoscarino)

The girl whom Spencer was cheating on Teddy with. Skyler and Teddy became friends afterward, then she became [[OfficialCouple PJ's girlfriend]].
* TheDitz: She makes PJ look a genius by comparison.
* TheBrainlessBeauty
* HeterosexualLifePartners: With Teddy--she sometimes took this role when Ivy is not around.
* OfficialCouple: With PJ.

!!Mary Lou Wentz
Ivy's mother
* BlackBestFriend: For Amy, most of the time.
* FriendlyEnemy: Sees Amy as this
** FriendlyRivalry
* SassyBlackWoman
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