Melvyn Douglas
— Jerome 'Jerry' Marvin
Ruth Hussey
— Professor Susan Drake
Ellen Drew
— Babe Marvin
Charles Coburn
— Professor Drake
John Hubbard
— Tom Drake
Harvey Stephens
— Dr. Cassell
Theresa Harris
— Hattie
Hooper Atchley
— Ticket Man (uncredited)
Irving Bacon
— Doorman (uncredited)
Brooks Benedict
— Concert Attendee (uncredited)
George Beranger
— Waiter (uncredited)
Betty Blythe
— Minor Role (uncredited)
Lloyd Bridges
— Taxi Driver (uncredited)
Barbara Brown
— Shipboard Passenger (uncredited)
Hobart Cavanaugh
— Shipboard Passenger (uncredited)
Grace Darmond
— Minor Role (uncredited)
Thornton Edwards
— Cuban Driver (uncredited)
Bob Evans
— Black Man (uncredited)
Edward Fielding
— Dr. Mandel (uncredited)
Martín Garralaga
— Cuban Driver (uncredited)
Lawrence Grant
— Dr. Holgarth (uncredited)
Chuck Hamilton
— Sailor (uncredited)
Sam Harris
— Concert Attendee (uncredited)
Arthur Stuart Hull
— Shipboard Passenger (uncredited)
Crauford Kent
— Dr. Jenkins - Ship's Doctor (uncredited)
Paul Lopez
— Cuban Official (uncredited)
George McKay
— Steward (uncredited)
Paul McVey
— Minor Role (uncredited)
John Merton
— Officer (uncredited)
Harold Miller
— Shipboard Passenger (uncredited)