Stephen Boyd
Grant
Raquel Welch
Cora
Edmond O'Brien
General Carter
Donald Pleasence
Dr. Michaels
Arthur O'Connell
Col. Donald Reid
William Redfield
Capt. Bill Owens
Arthur Kennedy
Dr. Duval
Jean Del Val
Jan Benes
Barry Coe
Communications Aide
Ken Scott
Secret Service
Shelby Grant
Nurse
James Brolin
Technician
Brendan Fitzgerald
Wireless Operator
Brendon Boone
Military Policeman (uncredited)
James Doohan
Dr. Sawyer (Hypothermia technician) (uncredited)
Kenneth MacDonald
Henry - Heart Monitoring (uncredited)
Christopher Riordan
Young Scientist (uncredited)