Unknown Island

Virginia Grey

Carole Lane

Phillip Reed

Ted Osborne

Richard Denning

John Fairbanks

Barton MacLane

Capt. Tarnowski

Dick Wessel

Sanderson, 1st Mate

Dan White

Crewman Edwards

Harry 'Snub' Pollard

Extra in Dive, Pointing Out Tarnowski

Ray Corrigan

Monster (uncredited)