TV child star of the '70s, Dickie Roberts is now 35 and parking cars. Craving to regain the spotlight, he auditions for a role of a normal guy, but the director quickly sees he is anything but normal. Desperate to win the part, Dickie hires a family to help him replay his childhood and assume the identity of an average, everyday loser.

Joe Dirt is a janitor with a mullet hairdo, acid-washed jeans and a dream to find the parents that he lost at the Grand Canyon when he was a belligerent, trailer park-raised eight-year-old. Now, blasting Van Halen in his jacked-up economy car, the irrepressibly optimistic Joe hits the road alone in search of his folks.

Philip Van Horn, who left his small town a long time ago to become a Hollywood actor and hasn't had any success at that, returns to the town for a visit. There he is uniformally met like some kind of celebrity and movie star. He uses it to impress his (and everybody's) school love Dorothy, her life now a grey boring experience.

Four skaters follow their idol on his summer tour in an attempt to get noticed, get sponsored, and become stars themselves.