John Agar
Prof. Clete Ferguson
Robert Williams
George Johnson
Nestor Paiva
Captain Lucas
Grandon Rhodes
Jackson Foster
Charles Cane
Police Captain
Ricou Browning
The Creature (some scenes)
Ben Chapman
The Creature (some scenes)
Tom Hennesy
The Creature (some scenes)
Ken Peters
WNTV Newscaster
Diane DeLaire
Miss Abbott, chimp trainer
Robert Nelson
Mack, a professor
Brett Halsey
First Student in Car (Driver)
Don C. Harvey
Rescue Party Leader
Robert Wehling
Joe (searchlight man)
Bill Young
Policeman at Motel
Julian Fant
Guy in Convertible
Jack Gargan
Police Boat Captain
Judeena Blackmer
Falling Child
Sally Baskin
Running Child
Mildred Baskin
Running Woman
Sydney Mason
Police Radio Operator
Loretta Agar
Woman on Boat
Charles Gibb
Policeman on Beach
Mike Doyle
Policeman on Beach
Betty Jane Howarth
Oceanarium Screamer
Patricia Powers
Girl in Convertible
Charles Victor
Police Boat Helmsman
Robert F. Hoy
Charlie (uncredited)