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