Jack Lemmon
as C.C. Baxter

Shirley MacLaine
as Fran Kubelik

Fred MacMurray
as Jeff D. Sheldrake

Ray Walston
as Joe Dobisch

Jack Kruschen
as Dr. Dreyfuss

David Lewis
as Al Kirkeby

Hope Holiday
as Mrs. Margie MacDougall

Joan Shawlee
as Sylvia

Naomi Stevens
as Mrs. Mildred Dreyfuss

Johnny Seven
as Karl Matuschka

Joyce Jameson
as The Blonde

Willard Waterman
as Mr. Vanderhoff

David White
as Mr. Eichelberger

Edie Adams
as Miss Olsen

Dorothy Abbott
as Office Worker (uncredited)

Ralph Moratz
as Office Worker (uncredited)

Joe Palma
as Office Maintenance Man (uncredited)

Bill Baldwin
as TV Movie Host (uncredited)

Benny Burt
as Charlie - Bartender (uncredited)

Lynn Cartwright
as Elevator Supervisor with Clicker (uncredited)

Mason Curry
as Bit Part (uncredited)

David Macklin
as Messenger (uncredited)

Hal Smith
as Man in Santa Claus Suit (uncredited)

Paul Bradley
as Office Worker (uncredited)

Steve Carruthers
as Restaurant Patron (uncredited)

Dick Cherney
as Bar Patron (uncredited)

Franklyn Farnum
as Office Worker (uncredited)

Herschel Graham
as Restaurant Patron (uncredited)

Lars Hensen
as Office Worker (uncredited)

Eugene Jackson
as Office Worker (uncredited)

Frances Weintraub Lax
as Mrs. Lieberman (uncredited)

William Meader
as Executive (uncredited)

Monty O'Grady
as Office Worker (uncredited)

Paul Power
as Bar Patron (uncredited)

Tony Regan
as Executive (uncredited)

Clark Ross
as Restaurant Patron (uncredited)

Norman Stevans
as Office Worker (uncredited)

Sid Troy
as Williams (uncredited)