After being kicked out of his rock band No Vacancy, guitarist Dewey Finn pretends to be his roommate Ned Schneebly to take a substitute teaching job at the prestigious Horace Green prep school. Initially neglecting his duties, Dewey soon discovers the musical talent of his fifth-grade students and decides to form a rock band from them to win the upcoming Battle of the Bands contest. The band is a secret but as the rehearsals progress, tensions rise when Dewey's deception is exposed, leading to his firing and parental disapproval. Defying the odds, the students break out of school to join Dewey for the competition, where their performance captivates the audience and earns them respect. The story blends humor, music, and heart, showing how passion and teamwork can transform both the students and Dewey's own life.