The Unknown Terror

John Howard

Dan Matthews

Mala Powers

Gina Matthews

Paul Richards

Peter Morgan

May Wynn

Concha Ramsey

Gerald Milton

Dr. Ramsey

Duane Grey

Lino

Richard Gilden

Raoul Koom

Martín Garralaga

Lead Villager

Patrick O'Moore

Dr. Willoughby

William Hamel

Mr. Trainor

Charles Grey

Jim Wheatley / ?The Monster Man

Charles Postal

Higgs (butler)

Sir Lancelot

Sir Lancelot

Charles Cirillo

Native (uncredited)

Jim Whitecloud

Native (uncredited)