Jerry Lewis as Clayton Poole

Marilyn Maxwell as Carla Naples

Connie Stevens as Sandra Naples

Salvatore Baccaloni as Gigi 'Papa' Naples

Reginald Gardiner as Harold Hermann

Ida Moore as Miss Bessie

Gary Lewis as Young Clayton

Isobel Elsom as Mrs. Van Cleeve

James Gleason as Doc Simpkins

Hans Conried as Mr. Wright

Hope Emerson as Mrs. Rogers

Alex Gerry as Judge Jenkins

Mary Treen as Nurse

Judy Franklin as Young Carla

Will Wright as Fire Chief (uncredited)

Mary Foran as Miss Menefee (uncredited)

Dickie Humphreys as Dancer / Actor (uncredited)

Jack Benny as Carlos, the matador (uncredited)