* ActorAllusion: Taylor makes it quite clear she's attending Yale following high school. Interestingly, Monique Coleman [[Series/GilmoreGirls has already attended]], and she was even on the paper.
* AdoredByTheNetwork:
** Disney Channel (at least in Australia) once had a tendency to overpromote any of the films if it's set to air within a week. Almost every single commercial will have at least one ad about it. Considering that, at least between 2005 - 2010, the film aired once a month, this was quite common.
** Since 2015, Disney's main movie channel in Australia tends to play the third film every week, and will commonly play songs from the three films between movies.
* CutSong
** The [[http://www.youtube.com/watch?v=ir38tIOQdT0 Humuhumunukunukuapuaa]] song and scene were cut from the televised version of ''High School Musical 2''. They reinstated it on the DVD and in the stage adaptation.
** There was also a song recorded for the 3rd movie called "Last Chance" that never made it into the movie apart from the reprise in the [[http://youtu.be/wWq9E6JBxCw medley]] of most of the songs in the movie. A [[http://youtu.be/ewpi5_39-Fw 40 second preview]] leaked in 2008 before the movie came out.
** In the first movie, there were a few songs that didn't make the cut. The love song "I Can't Take My Eyes Off Of You" was recorded by the four main leads (kind of {{Squick}}y because [[BrotherSisterIncest two of them played siblings]] and ended up on the album and as a [[http://youtu.be/uSBoARL2N3g bonus music video]] on the DVD (it's made to look like they're all recording the song but Zac Efron is there instead of Drew Seeley [[TalentDouble who did most of the singing for Zac's character]]. It also made it into the play version of the movie a duet between Troy and Gabriella, as did "[[http://youtu.be/ZHXU_wiWb5M Cellular Fusion]]" and "[[http://youtu.be/qJA9BTwmHTs Counting on You]]" but the song between Mrs. Darbus and Coach Bolton seems to be lost forever.
* DawsonCasting:
** Many of the actors were actually in their early 20s, though when the films initially started, most of the characters were played by people close to their actual age. Taylor's actress, Monique Coleman, was 26 at the time of the first film.
** Averted by Austin Butler in the spin-off film, who was nineteen and playing a college freshman. Likewise [[Series/GoodLuckCharlie Bradley Steven Perry]] as Sharpay's rival.
* DevelopmentHell: A fourth movie was announced back in 2009 and casting had begun around 2016. We haven't heard anything about it since then.
* DivorcedInstallment: The film originated as a third ''Grease'' film, where Britney Spears and Justin Timberlake would have played the children of Sandy and Danny - with the Sharpay-type character being Rizzo's daughter (played by Christina Aguilera).
* DyeingForYourArt: Zac Efron had to practice basketball three hours a day during the first movie.
* FakeAmerican: Oleysa Rulin (Kelsi) is a marginal example, as she's Russian born but was raised in America.
* FollowTheLeader: ''High School Musical'''s success was a clear factor in the format of ''{{Series/Glee}}'' - to the point that in its early days, people thought it was a {{Deconstruction}} of ''HSM''. ''Film/CampRock'' and ''Film/{{Descendants}}'' are also clearly inspired by it. Nickelodeon also produced the similar ''Spectacular''.
* GenreRelaunch: Disney's first successful live-action movie musical, discounting productions of old musicals, since ''Film/PetesDragon1977'' killed the genre nearly thirty years prior.
* HostilityOnTheSet: It was rumoured that Ashley Tisdale and Lucas Grabeel didn't get along during the first movie.
* IWantYouToMeetAnOldFriendOfMine:
** Prior to the first film, Olesya Rulin (Kelsi) and Lucas Grabeel (Ryan) had been in ''[[Film/{{Halloweentown}} Halloweentown High]]'' together, as Natalie the troll and Ethan the warlock, respectively.
** Both Monique Coleman and Vanessa Hutchens had recurring roles alongside Ashley Tisdale in ''Series/TheSuiteLifeOfZackAndCody''. Creator/ZacEfron also guest-stared in a season two episode, playing an anti-environmentalist who [[SlapSlapKiss slap-slap-kisses]] [[SoapboxSadie Tisdale's character]].
* IncestuousCasting: InUniverse. One character remarks that if Sharpay could find a way to play both Romeo and Juliet, Ryan would be out of a job, suggesting that the two have played romantic partners in the past.
* NonSingingVoice: Zac Efron's singing in the first movie is done by Drew Seeley. This is because Troy was envisioned as a TenorBoy, and Zac is a baritone range. Troy's vocal range is adjusted in the sequels as a result.
* TheOtherMarty: Cassie Steele was cast as Gabriella based on her performance in ''Full Court Miracle'', but she had to drop out due to commitments with ''Degrassi: The Next Generation''.
* PlayingAgainstType: Oddly, Ashley Tisdale as Sharpay - her previous Disney role was Maddie in ''Series/TheSuiteLifeOfZackAndCody'', [[HairOfGoldHeartOfGold a completely]] [[NiceGirl different role.]] If you want to go into detail, Ashley basically played a bitchy version of London in these movies. Lampshaded in an episode of the sitcom where Maddie tries out for Sharpay in her school's production of it, and gets told she's too nice for the role.
* RomanceOnTheSet: Between Zac Efron and Vanessa Hudgens, who were together for over five years. They confessed to liking each other during the first film and got together during the second. (Although they hid it for as long as they could to avoid media attention). Kenny Ortega admitted that he'd noticed their chemistry since the beginning, and deliberately paired them during auditions.
* SleeperHit: Seriously, '''nobody''' thought this Disney Channel Original Movie would end up being a giant hit that would encapsulate the late 2000s.
* StarMakingRole: For Zac Efron & Vanessa Hudgens. It's hard to believe that Ashley Tisdale was a more recognisable name than them at the time.
* ThrowItIn:
** According to the pop-up edition to the first movie, the scene where Sharpay kicks a bathroom door was ad-libbed.
** Corbin Bleu randomly decided to wear three different watches at once, which can be seen at Chad's first scene in the film.
* WhatCouldHaveBeen:
** Lucas Grabeel wanted Ryan to be gay (and possibly end up with Chad), but then the MoralGuardians came. This didn't stop "I Don't Dance" from happening though.
** Ashley Tisdale auditioned for Gabriella, but got given the role of Sharpay instead.
** Matthew Underwood from ''{{Series/Zoey 101}}'' was offered the role of Troy, but couldn't take it due to his contract with Nickelodeon.
** A duet was planned between Ms Darbus and Coach Bolton, but it never got filmed. Stage versions usually have them sing.
* TheWikiRule: [[http://high-school-musical.wikia.com/wiki/Main_Page The High School Musical Wiki]], and another [[http://highschoolmusicalsaga.wikia.com/wiki/High_School_Musical_Wiki High School Musical Wiki]].