Unemployed Dewey Finn (Jack Black) is fired from his rock band No Vacancy. His roommate Ned Schneebly (Mike White), is pressured by his girlfriend, Patty Di Marco (Sarah Silverman), to evict Dewey unless he starts paying rent. Dewey answers a phone call intended for Ned from Rosalie Mullins (Joan Cusack), the principal of a prestigious prep school, offering Ned a job. Dewey impersonates Ned and takes the substitute teacher position for a fourth-grade class. When Dewey, although uninterested in teaching, overhears their music class, he realizes they have musical talent. He sets the class a school project: form a band and win the Battle of the Bands, where No Vacancy are competing. As part of their training, Dewey teaches the history of rock music. He befriends Principal Mullins by playing her favorite song "Edge of Seventeen" by Stevie Nicks on a jukebox. The class auditions for the Battle of the Bands, but are rejected for lateness. With the help of the band manager, pupil Summer Hathaway (Miranda Cosgrove), Dewey persuades the managers to let the students perform by claiming the students are orphans with a rare blood disease. Ned receives a paycheck from the school and realizes that Dewey has been impersonating him. At that evening's parent-teacher conference, the suspicious parents question Dewey about their children's new interest in rock music. Ned and Patty appear with the police and expose Dewey. Dewey admits everything and is fired. After an argument with Patty that results in her leaving the house that night, Ned admits that he still misses playing music and thinks that it's time that Dewey moved out. The next day, the class decides to go ahead with the Battle of the Bands performance and recruit the sacked Dewey to lead them. Mullins is pressured all day with numerous complaints from all the parents until she leaves the room and sees a teacher searching for the kids. She realizes that the kids have gone missing. Mullins and the parents go to the venue to take their children back. Ned and Patty see the Class and Dewey getting ready to go to the venue and Patty threatens to call the police again. But Ned decides to go to the concert and closes the door on Patty in the middle of her rant. The class band, the School of Rock, plays an original song written by their lead guitarist, Zack, impressing the audience. Despite winning over the crowd, School of Rock loses to No Vacancy. However, the winning acceptance is booed at and the crowd demands School of Rock come on for an encore. Sometime later, Dewey opens the School of Rock, an after-school program where he continues to coach the class and Ned teaches beginner guitar players. The band plays during the end credits, and they even break the fourth wall by singing "The movie is over, but we're still on screen".
- Simba, Simon, Crash Bandicoot, the Regular Show gang, Dr. Rabbit, Dr. Brushwell, Ash and their friends, Littlefoot and his friends, the Jungle Crew, Mickey Mouse, Bugs Bunny, Osmosis Jones, Shrek, Princess Fiona, Donkey, Dragon, Puss in Boots, the Teen Titans, Rapunzel, Flynn Rider, the Fraggle Rock Animated gang, Spongebob, Ryan, Ash, Tai, Littlefoot, Alex, Simba, Stan, Greg, DJ Tanner, Malcolm, the Kids Next Door Cosplay Gang, Reese Ambler, Rydell, Becky, Dylan and their friends and the rest of the characters will guest star in this film.