Nathan Lane

Character: Spot Helperman / Scott Leadready II / Scott Manly-Manning (voice)

Kelsey Grammer

Character: Dr. Ivan Krank (voice)

Shaun Fleming

Character: Leonard Amadeus Helperman (voice)

Debra Jo Rupp

Character: Mrs. Mary Lou Moira Angela Darling Helperman (voice)

David Ogden Stiers

Character: Mr. Jolly (voice)

Jerry Stiller

Character: Pretty Boy (voice)

Paul Reubens

Character: Dennis (voice)

Megan Mullally

Character: Adele (voice)

Wallace Shawn

Character: Principal Crosby Strickler (voice)

Rob Paulsen

Character: Ian Wazselewski (voice)

Jay Thomas

Character: Barry Anger (voice)

Estelle Harris

Character: Mrs. Boogin (voice)

Genie Francis

Character: Marsha / Marcia (voice)

Anthony Geary

Character: John / Juan (voice)

Rosalyn Landor

Character: The Blue Fairy (voice)

David Maples

Character: Beefeater (voice)

Pamela Adlon

Character: Trevor / Taylor / Tyler (voice)

Timothy Stack

Character: Father (voice)

Emma Steinkellner

Character: Little Girl (voice)

Ken Swofford

Character: Officer White (voice)

Lauren Tom

Character: Younghee (voice)

Mae Whitman

Character: Leslie Dunkling (voice)

Kevin Michael Richardson

Character: Conductor (voice)