Steve Karnes
Gene Evans
Prof. James Bickford
André Morell
Naval Commader, at the "Valkyrie" wreck (uncredited)
Howard Lang
Dialogue Scientist at Conference (bit)
Leonard Sachs
Scientist at Conference (uncredited)
Ernest Blyth
TV Newscaster (uncredited)
Neal Arden
Man Listening to Car Radio (uncredited)
Paul Beradi
PLA Radio Operator (uncredited)
Max Faulkner
Dr. Sampson's Helicopter Pilot (uncredited)
Neil Hallett
French Radio Officer (uncredited)
André Maranne
The Radar Operator, at the radar room (uncredited)
Derren Nesbitt
Naval Officer in Situation Room (uncredited)
Guy Standeven
Jean Trevethan
Leigh Madison
John
John Turner
Dr. C. A. Morris, the village doctor
Alastair Hunter
Senior Admiral, at the Admiralty
Lloyd Lamble
Dr. Sampson, the paleontologist
Jack MacGowran
Mini Submarine Officer
Maurice Kaufmann
Tom Trevethan
Henri Vidon
Photo Lab Aide
Patrick Jordan
Screenplay
Eugène Lourié
Director
Production Design
Special Effects
Willis H. O'Brien
Visual Effects
Camera Operator
Desmond Davis
Douglas Hickox
Daniel James
Story
Robert Abel
Alan J. Adler
Director of Photography
Ken Hodges
Editor
Lee Doig
Producer
Ted Lloyd
David Diamond
Original Music Composer
Edwin Astley
Art Direction
Harry White
Sound Editor
Richard Marden
Pete Peterson
Jack Rabin
Makeup Artist
Jimmy Evans
Louis DeWitt
Irving Block
Hairstylist
Bernadette Ibbetson
First Assistant Director
Kim Mills
Continuity
Jennifer Herrinshaw
Wardrobe Master
Freda Gibson
Sound
Sid Wiles
Conductor
Production Manager
Jacques de Lane Lea