Noah Beery Jr.

Jan Trevor

Dorothy Short

Mona Andrews

Harry Woods

Borno

Walter Miller

Dr. Frank Bracken

John Davidson

Prince Samu

William Desmond

Allen

Russ Powell

Henry Andrews

Don Brodie

Dr. Carl Neff

Harry Worth

Dr. Carl Neff

Dickie Jones

Jan Trevor as a Boy

Eddie Kane

Gen. Tichak

Stanley Andrews

Emperor Mena

Richard Alexander

Navigator (archive footage)

King Baggot

Dr. Pierce

Eric Mayne

Doctor at Conference

J.P. McGowan

Freighter Captain

Eddie Parker

Emperor's Guard / Mu Sentry

Buddy Roosevelt

Batu

Hal Taliaferro

Lancer Officer-in-Charge