John Agar
Prof. Clete Ferguson
John Agar
Prof. Clete Ferguson
Lori Nelson
Helen Dobson
John Bromfield
Joe Hayes
Nestor Paiva
Captain Lucas
Grandon Rhodes
Jackson Foster
Dave Willock
Lou Gibson
Robert B. Williams
George Johnson
Charles Cane
Police Captain
Loretta Agar
Woman on Boat (uncredited)
Bill Baldwin
Patrol Boat Dispatcher (voice / uncredited)
Jere Beery
Photographer (uncredited)
Ricou Browning
The Gill Man (in water) / Lab Technician (uncredited)
Diane DeLaire
Miss Abbott (uncredited)
Mike Doyle
Cop (uncredited)
Clint Eastwood
Jennings (uncredited)
Jack Gargan
Skipper (uncredited)
Charles Gibb
Cop (uncredited)
Brett Halsey
Pete (uncredited)
Don C. Harvey
Mac - Spotlight Party Leader (uncredited)
Tom Hennesy
The Gill Man (on land) / Marineland Diver (uncredited)
Don House
Diver (uncredited)
Robert F. Hoy
Charlie (uncredited)
Ned Le Fevre
Newscaster (uncredited)
Sydney Mason
Police Announcer (uncredited)
Robert Nelson
Dr. McCuller (uncredited)
Patricia Powers
Girl in Convertible
Bert Stevens
Search Party Member (uncredited)
Charles Victor
Policeman (uncredited)
Robert Wehling
Joe (uncredited)
James R. Wolfe
Man at Tank (uncredited)
Jack Arnold
Director
Martin Berkeley
Screenplay
William Alland
Story
Scotty Welbourne
Director of Photography
Jack Kevan
Creature Design
William Alland
Producer
William Lava
Original Music Composer
Herman Stein
Original Music Composer
Paul Weatherwax
Editor
Alexander Golitzen
Art Direction
Alfred Sweeney
Art Direction
Russell A. Gausman
Set Decoration
Julia Heron
Set Decoration
Bud Westmore
Makeup Artist
Jack A. Bolger, Jr.
Sound
Leslie I. Carey
Sound
Ben Hendricks
Sound Editor
Albert E. Kennedy
Sound Editor
Jay A. Morley Jr.
Costume Designer
Joan St. Oegger
Hairstylist
Edward Dodds
Unit Production Manager
Fred Frank
Assistant Director
Tom Hennesy
Stunts
Don House
Stunts
Robert F. Hoy
Stunts
Ginger Stanley
Stunts
Joseph Gershenson
Music Supervisor
Henry Mancini
Music
Milton Rosen
Music
Ethmer Roten
Musician
Hans J. Salter
Music
Frank Skinner
Music