Dr. Edward Morbius
Altaira Morbius
Commander John J. Adams
Lt. 'Doc' Ostrow
Lt. Jerry Farman
Cookie
Chief Engineer Quinn
Bosun
Crewman Grey
Crewman Youngerford
Crewman Strong
Crewman Randall
Crewman Lindstrom
Crewman Moran
Crewman Nichols
Crewman Silvers
Crewman (uncredited)
Narrator (voice) (uncredited)
Robby the Robot (interior) (uncredited)
Robby the Robot (voice) (uncredited)