Jerry Lewis as Stanley Belt

Ina Balin as Ellen Betz

Everett Sloane as Caryl Fergusson

Phil Harris as Chic Wymore

Keenan Wynn as Harry Silver

Peter Lorre as Morgan Heywood

John Carradine as Bruce Alden

Hans Conried as Prof. Mulerr

Quinn O'Hara as Cigarette Girl

Richard Deacon as Sy Devore

Scatman Crothers as Shoeshine Boy

Del Moore as Policeman

Neil Hamilton as The Barber

Buddy Lester as Copa Café MC

Nancy Kulp as Helen, Theatergoer

Lloyd Thaxton as Lloyd

Norman Alden as Bully at the Gym

Jack Albertson as Theatergoer with Helen

Henry Slate as Paul

Gavin Gordon as Executive on Golf Course

Ned Wynn as Band Member

Mantan Moreland as Barber Shop Porter

Dave Willock as Alec (uncredited)

Fritz Feld as Maitre D'

Hedda Hopper as Herself

Joan Swift as Girl (uncredited)

Sherwood Price as Bellboy (uncredited)

Bob May as Fireworks Boy (uncredited)

Norman Leavitt as Newsboy (uncredited)

Jerry Dexter as (uncredited)

Fay DeWitt as Woman at Party (uncredited)

Chick Chandler as Hedda Hopper's Escort (uncredited)

Don Brodie as Bowler (uncredited)

Richard Bakalyan as Boy at Spring Hop (uncredited)

Ed Wynn as Ed Wynn

George Raft as George Raft

Rhonda Fleming as Rhonda Fleming