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
Makeup Designer
Milicent Patrick
Creature Design
Makeup Artist
Bud Westmore
Stunts
Ted White
Director
Jack Arnold
Al Wyatt Sr.
Director of Photography
William E. Snyder
Producer
William Alland
Hans J. Salter
Screenplay
Harry Essex
Herman Stein
Arthur A. Ross
Editor
Ted J. Kent
Jack N. Young
Driver
James R. Wolfe
Gene Poole
Ginger Stanley
Idea
Assistant Director
Russ Haverick
Unit Manager
Foster Thompson
Grip
Everett Brown
Musician
Ethmer Roten
Jack Kevan
Chris Mueller
Sound Editor
Ray Craddock
Robert Hickman
Albert E. Kennedy
Art Direction
Hilyard M. Brown
Hairstylist
Joan St. Oegger
Story
Maurice Zimm
Set Decoration
Ray Jeffers
Russell A. Gausman
Bernard Herzbrun
Sound
Joe Lapis
Leslie I. Carey
Still Photographer
Scotty Welbourne
Music
Milton Rosen
Robert Emmett Dolan
Underwater Camera
James Curtis Havens
E. Thomas Case
Fred Frank
Music Director
Joseph Gershenson