Dr. David Reed
Richard Carlson
Kay Lawrence
Julie Adams
Narrator (voice) (uncredited)
Art Gilmore
Tomas (uncredited)
Perry Lopez
Dr. Matos (uncredited)
Sydney Mason
Luis (uncredited)
Rodd Redwing
Old Man (uncredited)
James Miller
Dr. Mark Williams
Richard Denning
Dr. Carl Maia
Antonio Moreno
Captain Lucas
Nestor Paiva
Dr. Edwin Thompson
Whit Bissell
Zee
Bernie Gozier
Chico
Henry A. Escalante
The Gill Man In Water (uncredited)
Ricou Browning
The Gill Man On Land (uncredited)
Ben Chapman
Stunt Double
Polly Burson
Original Music Composer
Henry Mancini
Creature Design
Milicent Patrick
Makeup Designer
Makeup Artist
Bud Westmore
Stunts
Ted White
Director
Jack Arnold
Al Wyatt Sr.
Editor
Ted J. Kent
Director of Photography
William E. Snyder
Screenplay
Harry Essex
Arthur A. Ross
Hans J. Salter
Producer
William Alland
Herman Stein
Ginger Stanley
Jack N. Young
Musician
Ethmer Roten
Assistant Director
Russ Haverick
Driver
James R. Wolfe
Idea
Grip
Everett Brown
Gene Poole
Unit Manager
Foster Thompson
Robert Hickman
Sound Editor
Ray Craddock
Albert E. Kennedy
Jack Kevan
Chris Mueller
Story
Maurice Zimm
Set Decoration
Ray Jeffers
Art Direction
Hilyard M. Brown
Bernard Herzbrun
Hairstylist
Joan St. Oegger
Russell A. Gausman
Sound
Leslie I. Carey
Joe Lapis
Music
Milton Rosen
Underwater Camera
James Curtis Havens
Robert Emmett Dolan
Still Photographer
Scotty Welbourne
E. Thomas Case
Fred Frank
Music Director
Joseph Gershenson