Ralph Macchio as 17 Year Old Tim (voice)

Eric Idle as Evil Martin (voice)

Hynden Walch as Jenny Mcbride (voice)

Harvey Korman as Floyd (voice)

Andrea Martin as Muriel (voice)

William H. Macy as Justin (voice)

Dom DeLuise as Jeremy (voice)

Peter MacNicol as Narrator (voice)

Andrew Ducote as 10 Year Old Timmy (voice)

Arthur Malet as Mr. Ages (voice)

Doris Roberts as Auntie Shrew (voice)

Phillip Van Dyke as Young Martin (voice)

Darleen Carr as Helen (voice)

Jamie Cronin as Teresa (voice)

Jameson Parker as Troy (voice)

Phillip Glasser as Reformed 19 Year old Martin (voice)

Whitney Claire Kaufman as Cynthia (voice)

Steve Mackall as Professor Valentine (voice)

Kevin Michael Richardson as Brutus (voice)

Meshach Taylor as Cecil (voice)

Debi Mae West as Mrs. Jonathan Brisby (voice)

Al Jarreau as The Balladeer (voice)

Bobbi Page as The 2nd Balladeer (voice)

Beth Andersen as Chorus (voice) (uncredited)