Dr. Sigmund Walters

John Carradine

Paula Dupree, the Ape Woman

Acquanetta

Beth Colman

Evelyn Ankers

Fred Mason

Milburn Stone

John Whipple

Lloyd Corrigan

Dorothy Colman

Martha Vickers

Nurse Strand

Fay Helm

Curley Barret

Vince Barnett

William Edmunds

Gruen

Paul Fix

Grant Withers

Roustabout (uncredited)

Fred Aldrich

Dock Ticket Office Clerk

Harry Holman

Fred Mason (in long shots) (archive footage / uncredited)

Clyde Beatty

End Narrator (voice)(uncredited)

Turhan Bey

Dock Spectator (uncredited)

Eddie Borden

Cheela the Gorilla (uncredited)

Ray Corrigan

Curley (uncredited)

Russell Custer

Beth's Murdered Neighbor (uncredited)

Fern Emmett

Trapeze Artist (uncredited)

Virginia Engels

Coroner (uncredited)

Gus Glassmire

Sheriff (uncredited)

William Gould

Al (uncredited)

Al Haskell

Ship's Captain (archive footage)

Tom London

Cop (uncredited)

Charles McAvoy

Handler (uncredited)

Frank Mitchell

Dock Worker (uncredited)

Charles Morton

Jake - Handler (uncredited)

Edward Peil Sr.

Man on Dock (uncredited)

Stanley Price

Attendant (uncredited)

Joey Ray

Roustabout (uncredited)

Cap Somers

Ringmaster (uncredited)

Ray Walker

Tony - Handler (uncredited)

Anthony Warde