[[quoteright:342:http://static.tvtropes.org/pmwiki/pub/images/thirteengoingonthirty.jpg]]
->'''Matt''': You can't just turn back time.
->'''Jenna''': Why not?

''Thirteen Going On Thirty'' is a RomanticComedy movie about a girl named Jenna Rink (Creator/JenniferGarner) who is 13 and suffers from the ageless drama of 13-year-old girls: she doesn't have enough boobs, she doesn't have enough cool clothes, [[JerkJock she doesn't have a beautiful and popular boyfriend]], and she definitely doesn't [[InWithTheInCrowd have friends among the In Crowd]].

As a solution to this, she [[BeCarefulWhatYouWishFor wishes]] to become older and successful and beautiful and popular and pretty much everything else. So, with [[AppliedPhlebotinum a little help from a magic dust]], she ages seventeen years in a blink, and wakes up as powerful magazine editor, whose best friend is Lucy Wyman, aka Tom-Tom (JudyGreer) [[AlphaBitch the old queen bee]] at her school.

The only problem is: she doesn't remember a thing of how she passed the past years. Matt ([[Film/TheAvengers Mark Ruffalo]]), [[NerdsAreSexy a nerd]] who was her only friend at high school, helps her to find herself; but what if she does not like how she turned out to be?

For the trope that this movie used to name, see OvernightAgeUp.
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!!This film provides examples of the following tropes:

* {{Adorkable}}: Teen!Jenna, both in the 80s and in 2004, and to a more meta extent, Jennifer Garner. If her utter enthusiasm and enjoyment of life doesn't get you, the Thriller dance will.
* AlphaBitch: Tom-Tom (a.k.a. Lucy) in her high school days.
* AmbiguouslyGay: Jenna's boss.
* AmbitionIsEvil: So, you want to be thirty AND have money AND power AND boobs? Absurd. The only way you'll ever have all that is if you became a Class A Bitch.
* AnguishedDeclarationOfLove: [[spoiler: Jenna to Matt, right before his wedding]].
* AppliedPhlebotinum: The film's events are set in motion by "magic dust."
* BrainyBrunette: Jenna, of course. Yes, she may have turned out to be a 30-year-old bitch, but she certainly isn't dumb.
* BlondesAreEvil: Tom-Tom, who is very blonde in the beginning of the movie.
* CerebusCallBack: The dream house Matt makes for Jenna's birthday is subject to two. It's introduced in a comical yet sweet scene. Later on in the film we find out that apparently Jenna threw the house at him after thinking he scared away the party guests. Also [[spoiler: after Matt refuses to leave Wendy]] she begs to have the house as something to remember him by and cries while looking at it.
* CharacterDevelopment: Jenna realizes that maybe there's more to life than money and success. Something more along the lines of Becoming A Better Person.
* CorruptTheCutie: In this case, Jenna kind of corrupts herself, but...
* DanceLine: Jenna does this during the Thriller dance part.
* DerailingLoveInterests/ DisposableFiance: [[spoiler: Averted. Matt refuses to leave Wendy for Jenna and she ends up wishing herself back to the age of 13 to fall in love with him the proper way. He simply never met Wendy in the first place or, if he did, was with Jenna at the time]].
* DotingParent
* EmbarrassingNickname: Tom-Tom. I mean, Tom-Tom?
** Not that Jenna's is any better - "Sweetbottom"? (Mind you, many men would agree it fits considering she's played by Jennifer Garner.) And Matt's junior high nickname was Beaver.
* EmotionalTorque: The always present Aaaaaaaw Sound, mostly. Specially at the end, [[spoiler: when the Loving Couple finally get together]].
* FallingInLoveMontage
* FamilyVersusCareer: Jenna has to choose: She gets True Love, or she gets a good job and a lot of money. There's more to the plot than that, but these are pretty much the basics of it.
* FashionMagazine: "Poise" magazine.
* FishOutOfTemporalWater: Jenna goes from being a teen in TheEighties to being an adult during the TurnOfTheMillennium. The movie ignores many of the problems (and humor) which might result from the TimeTravel aspect of the plot. Is Jenna going around as a 30-year-old high-powered magazine editor in 2004 thinking [[TheGreatPoliticsMessUp the Soviet Union still exists]] or that MichaelJackson is still black? Who knows, it's never brought up. However, a few jokes are brought up: she doesn't initially know what a cell phone ringing is, and she thinks Eminem is the candy brand.
* FriendsRentControl / BigFancyHouse : For a freelance photographer and a magazine editor who live single in NYC, both Jenna and Matt have pretty posh apartments. And [[spoiler: their "dream house" when they get married]] also seems pretty upscale.
* FutureMeScaresMe
* GenkiGirl: Jenna as an adult. Apparently she's not normally like that, thoroughly freaking out her co-workers.
* GirlNextDoor: Jenna and Matt grew up next door to each other.
* GirlPosse: The Six Chicks
* GrowingUpSucks
* HappilyEverAfter: What did you expect?
* HeyItsThatGuy: Jenna's boss is frikkin' [[Film/LordOfTheRings Gollum!]]
** Younger Matt is [[FostersHomeForImaginaryFriends Mac]] and older Matt is [[Film/TheAvengers Bruce Banner]].
*** Two of The Six Chicks are [[Series/PrettyLittleLiars Hanna Marin]] and [[Series/UnitedStatesOfTara Kate Gregson]]!
* HomeSweetHome
* HighSchool: The part between times that she doesn't remember, that is.
* HighSchoolSweethearts: Jenna and Matt, obviously. Averted because the first time around, they stopped being friends. Jenna's "sweetheart," presumably, was Chris, whom she took to prom.
* HorribleJudgeOfCharacter: Jenna concerning Lucy.
* InformedAbility: Jenna's redesign proposal for "Poise" looks about like a 13-year-old's attempt at a photo collage of her friends. Justified? Well, not the part where it gets an ovation from a room full of media professionals and someone resorts to corporate espionage to rip it off for their own magazine.
* JustFriends: Jenna and Matt.
* MarketBasedTitle: For no apparent reason, the movie was released in Australia and Brazil as ''Suddenly 30''.
* MichaelJacksonsThrillerParody: Jenna dances MichaelJackson's "Thriller" dance in a nightclub and this gets the party going...This could also be a ChekovsGag when we see her dancing by herself at her party in the beginning.
* TheMole: [[spoiler: Lucy, using Jenna's mailers,]] had been feeding a rival fashion magazine with ideas for articles that her magazine had been coming up with.
* NamesTheSame: [[Series/{{Awkward}} Jenna and Matty]]
* OvernightAgeUp
* PopularHistory: The version of 1987 in which 13-year-old Jenna lives like a modern-day '80s-themed party.
* RaceForYourLove: [[spoiler: Jenna rushing to catch Matt at his wedding.]]
* SeparatedAtBirthCasting: Christa Allen as Young Jenna. Jennifer Garner says that she looks identical to her when she was that age and the two were cast in similar roles in ''Ghosts Of Girlfriends Past''.
* SleepMask: Used by Jenna when she wakes up as adult.
* StepfordSmiler: Jenna, when she wakes up 30, finds she is not the nice young girl she used to be.
* TheReveal: Done ''twice'' because [[spoiler: the first-time viewers in the audience wouldn't know the significance of the letter from the rival Sparkle Magazine that turns up in her mail in the first reveal either]].
* OrWasItADream
* ResetButton
* RidiculouslySuccessfulFutureSelf
* TimeShiftedActor: Christa B Allen as young Jenna, Sean Marquette as young Matt and Alexandra Kyle as young Lucy.
* TrueLovesKiss: Again, what did you expect?
* VictoriousChildhoodFriend
* XMeetsY: {{Big}} meets RegardingHenry with liberal sprinkling of PeggySueGotMarried in reverse.
* YouCanLeaveYourHatOn: Jenna's boyfriend in a very-not-sexy scene.
** To "Ice Ice, Baby" by Music/VanillaIce, yet!
* WhenSheSmiles: The late night walk between Jenna and Matt.
** Surprisingly Lucy gets one too. Throughout the film if 'smiling' at all she is either smirking or has an obviously fake smile plastered over her face. However when Jenna plays Thriller in the club Lucy breaks into a massive happy grin and giddily runs off to join the dancing.
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