Gregory Peck

David Stillwell

Diane Baker

Shela

Walter Matthau

Ted Caselle

Robert H. Harris

Dr. Broden

Kevin McCarthy

Sylvester Josephson

Leif Erickson

The Major

Walter Abel

Charles Stewart Calvin

George Kennedy

Willard

Jack Weston

Lester

Anne Seymour

Frances Calvin

House Jameson

Bo

Hari Rhodes

Lt. Franken

Eileen Baral

Irene

Franklin Cover

Group Leader

Bill Baldwin

Robert Brubaker

Ann Doran

Tenant in Apartment 3R (uncredited)

Rian Garrick

Gerald Gordon

Damian O'Flynn

Bar Patron (uncredited)

Bill Quinn

Eddie - Bartender (uncredited)

Walter Reed

Reporter (uncredited)

Bert Stevens

Aline Towne

Dr. Broden's Receptionist (uncredited)

Howard Wendell

Myron Healey

Bar Patron Discussing Watermelon (voice) (uncredited)