History Trivia / HighSchoolMusicalTheMusicalTheSeries

** Saylor Bell Curda originally auditioned for the role of Nini Salazar-Roberts. She was one of the finalist for Nini before the role was given to Olivia Rodrigo. The crew loved Saylor Bell Curda so much they ended up contacting her again to audition for Season 3 for the role of Maddox.

** But averted by Dara Renee, who was 18 years old at the beginning of the series and plays Kourtney, a junior.
** Also averted by "the Freshman" (who is hilariously playing the macho adult character Coach Bolton), who is played by 15-year-old Spencer [=McConnell=].

* RealLifeRelative: Kourtney Greene's mother Michelle Greene is played by Dara Renee's real life mother Kimberly Brooks.

* WriteWhatYouKnow: In Season 4, it was revealed that Ricky has a 1.8 G.P.A. then the creator of the show Tim Federle posted on his Instagram story revealing that he had a 1.8 G.P.A. in High School with the hashtag #WriteWhatYouKnow.

** Tim Federle chose to end the series with season four, as he wasn't certain they'd be able to get a fifth season. If they did, though, the cast would have performed ''Film/TheGreatestShowman'' with Ricky playing Phillip Carlyle, Gina as Anne Wheeler, and Jet as P.T. Barnum.

** A minor one, but Dara Renee injured her ankle shortly before the filming of "Truth, Justice, and Songs in our Key" in episode six and therefore was unable to partake in the large dance number. As such, Larry Saperstein (Big Red) learned the choreography at the last minute to sub in while Kourtney stays on the balcony and sings.

* RealLifeRelative: Kourtney Greene's mother Michelle Greene is played by Dara Renee who plays Kourtney real life mother Kimberly Brooks.

* RealityWritesThePlot: Nini's extended absence during the third season, and her departure at the end, was due to Olivia Rodrigo's music career taking off between production of season two and three. As such she was only available for brief scenes near the start of the season, then some quick scenes in the finale before leaving for good.

** Matt Cornett is 21 playing a high school senior, and very much looks it. Many reviewers complained that his romantic scenes with Olivia Rodrigo were uncomfortable to watch because of the obvious age difference.
** Carlos and Seb, both sophomores, are played by 22-year-old Frankie Rodriguez and 21-year-old Joe Serafini. The other sophomore in the main cast, Ashlyn, is played by 20-year-old Julia Lester.

** But averted by Dara Renee, who is 18 years old and plays Kourtney, a junior.

** Other cast members Lester, Saperstein, and Bassett have also come out as LGBTQ and creator Tim Federle has expressed interest for having their respective characters explore their sexualities in future seasons. This came true for [[spoiler: Ashlyn]] in the third season.

* ActorSharedBackground: Nini is Filipino-American, just like her actress, Olivia Rodrigo. You can tell because Nini's mother and grandmother have Filipino ancestry, and Nini even calls her grandmother "Lola".

** Other cast members Lester, Saperstein, and Bassett have also come out as LGBTQ and creator Tim Federle has expressed interest for having their respective characters explore their sexualities in future seasons.
* RenewedBeforePremiere: Was renewed before the first season premiered, though it was delayed for a year due to the UsefulNotes/Covid19Pandemic.

* {{Fanon}}:
** Due to his role as Sharpay in the first season, many fans and fanworks interpret Seb as varying forms of nonbinary or genderqueer.
** Many fans agree that if Big Red is bi like his actor, then his ClosetKey is Ricky.

*** Seb was only planned to appear in two or three episodes, and doesn't even have any lines in the pilot. In the end he appeared in 9 out of 10 and was promoted to regular for season 2.

** Joshua Bassett and Olivia Rodrigo are both songwriters, and so are both of their characters.

* ActorAllusion: In during Miss Jenn's fantasy in "The Tech Rehearsal," she remarks that she's "more of an Glinda." Kate Reinders played Glinda in ''Theatre/{{Wicked}}'' in Chicago and on Broadway.

** Although not officially confirmed, it's an OpenSecret that Olivia Rodrigo and Joshua Bassett dated during production of the show's first season, and broke up at some point during the lengthy hiatus between the show's first and second seasons, with this experience inspiring Rodrigo to write her smash-hit "Driver's License", along with several other songs. This also overlaps with YourCheatingHeart as she was still with Ethan Wacker during the production of the first season, but it's unknown when at that point Olivia cheated on Ethan with Joshua.

** Although not officially confirmed, it's an OpenSecret that Olivia Rodrigo and Joshua Bassett dated during production of the show's first season, and broke up at some point during the lengthy hiatus between the show's first and second seasons, with this experience inspiring Rodrigo to write her smash-hit "Driver's License", along with several other songs.

* RomanceOnTheSet: Although not officially confirmed, it's an OpenSecret that Olivia Rodrigo and Joshua Bassett dated during production of the show's first season, and broke up at some point during the lengthy hiatus between the show's first and second seasons, with this experience inspiring Rodrigo to write her smash-hit "Driver's License".