There are several references to William Shakespeare's "The Twelfth Night," on which the movie is based. The school is called Illyria, which is the name of the country where the play takes place. Duke Orsino's character is based on Orsino, a duke. Duke's friends are named Toby and Andrew; in the play, Toby is Olivia's uncle and Andrew is one of her suitors. However, in the play, Viola is not impersonating her brother in particular, just a man, and she calls herself Cesario, which is the name of the restaurant seen where Sebastian/Viola breaks up with Monique and where Duke, Olivia, Eunice, and Sebastian/Viola briefly double date.
According to the audio commentary on the DVD, the opening to the movie was shot on the coldest day of June in the history of Vancouver.
On Viola's first day at Illyria, there is a sign for the school's play entitled "What You Will" which not coincidentally is the subtitle for the Shakespearian play upon which this film is based
The producers of this film initially wanted Jesse McCartney to play the role of Sebastian, because McCartney's facial features are similar to that of Amanda Bynes. McCartney was unavailable to shoot the film, so they cast James Kirk instead. Most of the cheerleaders also were the dancers in Reefer Madness: The Movie Musical (2005), which was also directed by Andy Fickman.
The song playing during the double date between Viola/Sebastian, Eunice, Duke, and Olivia is one of Sebastian's songs. Olivia reads the lyrics of the song out loud the first time she and Viola/Sebastian work as lab partners and later she recites the same lyrics to the real Sebastian.
When they first started filming, Amanda Bynes couldn't play soccer at all. Nevertheless, Bynes does most of her own playing in the movie.