Professor Julius Kelp/Buddy Love/Baby Kelp

Jerry Lewis

Stella Purdy

Stella Stevens

Dr. Hamius R. Warfield

Del Moore

Gibson

Henry Gibson

Millie Lemmon

Kathleen Freeman

Football Player

Med Flory

Mr. Elmer Kelp

Howard Morris

Mother Kelp

Elvira Allman

Man in Gym (uncredited)

Richard Kiel

Dr. M. Sheppard Leevee

Milton Frome

Football Player

Norman Alden

Edwina Kelp

Elvia Allman

Bartender

Buddy Lester

Football Player

Skip Ward

Rube

Doodles Weaver

English Boy

Marvin Kaplan

Gym Attendant (uncredited)

Murray Alper

College Student

David Landfield

College Student

Celeste Yarnall

Bored Man

Seymour Cassel

College Student

Francine York

Waitress (uncredited)

Stephanie Hill

College Student

Julie Parrish

Bartender

Dave Willock

Plumber (uncredited)

Billy Bletcher

Cab Driver

Mushy Callahan

College Student (uncredited)

Robert Donner

Salesman Clothier

Gavin Gordon

Narrator (voice) (uncredited)

Art Gilmore

Faculty Member

Joe Forte

Man In Gym

William Engesser

Cigarette Girl

Terry Higgins

Boy

Gary Lewis

Student at Senior Prom

Les Brown Jr.

College Faculty Member

Joseph Forte

Faculty Member at Senior Prom

Stuart Holmes

Faculty Member at Senior Prom

Forbes Murray

Musician - Percussionist

Emil Richards

Purple Pit Customer

Bert Stevens

Football Player

Roger Torrey

Himself

Les Brown