Cornelius
Roddy McDowall
Dr. Zira
Kim Hunter
General Winthrop
Harry Lauter
Aide
M. Emmet Walsh
Lawyer (as Roy E. Glenn Sr.)
Roy Glenn
Cardinal
Peter Forster
Army Officer
Norman Burton
Naval Officer
William Woodson
Orderly
Tom Lowell
Marine Captain
Gene Whittington
Curator
Donald Elson
TV Newscaster
Bill Bonds
Dr. Lewis Dixon
Bradford Dillman
Referee
Army Archerd
General Faulkner
James Bacon
Armando
Ricardo Montalban
Marine Corporal (uncredited)
John Alderman
General (uncredited)
Alan Baxter
Secretary of State (uncredited)
Jack Berle
Official at Briefing (uncredited)
Paul Bradley
German Newscaster (uncredited)
Karl Bruck
Undetermined (uncredited)
Sam Chew Jr.
Reporter (uncredited)
Robert Cole
Dr. Stephanie 'Stevie' Branton
Natalie Trundy
Talking Baby Chimp (uncredited) (voice)
Walker Edmiston
Spectator (uncredited)
Sig Frohlich
Helicopter Pilot (uncredited)
James W. Gavin
George Golden
James Gonzalez
Bodyguard (uncredited)
Joe Gray
Aide (uncredited)
Bob Harks
Nova (archive footage) (uncredited)
Linda Harrison
Reporter at Hotel (uncredited)
Elizabeth Harrower
Bystander (uncredited)
Shep Houghton
Dr. Otto Hasslein
Eric Braeden
Waiter (uncredited)
Joseph La Cava
Robert Nichols
Ron Pinkard
Heloise (uncredited)
Janos Prohaska
Tony Regan
Gen. Brody (uncredited)
Stephen Roberts
Hank Robinson
Control Room Officer (uncredited)
James B. Sikking
Jack Slate
Arthur Tovey
The President
William Windom
Hotel Receptionist (uncredited)
William Tregoe
British News Anchor (uncredited)
William Beckley
Dr. Milo
Sal Mineo
E-1
Albert Salmi
E-2
Jason Evers
Committee Chairman
John Randolph
Original Music Composer
Jerry Goldsmith
Characters
Pierre Boulle
Producer
Arthur P. Jacobs
Screenplay
Paul Dehn
Director
Don Taylor
Art Direction
William J. Creber
Jack Martin Smith
Stuart A. Reiss
Walter M. Scott
Special Effects Coordinator
Howard A. Anderson III
Director of Photography
Joseph F. Biroc
Editor
Marion Rothman
Sound
Theodore Soderberg
Dean Vernon
Associate Producer
Frank Capra, Jr.