Miss Paula White

Bessie Love

Lord John Roxton

Michael Rennie

Jennifer Holmes

Jill St. John

Sir John Roxton

Lewis Stone

Professor Challenger

Wallace Beery

Prof. George Edward Challenger

Claude Rains

Edward E. Malone

Lloyd Hughes

Manuel Gomez

Fernando Lamas

Professor Summerlee

Arthur Hoyt

Gladys Hungerford

Alma Bennett

Prof. Summerlee

Richard Haydn

Mrs. Challenger

Margaret McWade

David Holmes

Ray Stricklyn

Costa

Jay Novello

Austin, Challenger's Butler

Frank Finch Smiles

Native Girl

Vitina Marcus

Montana

Bull Montana

Zambo, Roxton's Servant)

Jules Cowles

Colin McArdle

George Bunny

Marquette (half-caste girl) (uncredited)

Virginia Brown Faire

Maj. Hibbard

Charles Wellesley

Lawyer advising the editor (uncredited)

Nelson McDowell

Marquette

Virginia Browne Faire

Himself

Arthur Conan Doyle

Extra

Gilbert Roland

Percy Potts

Leo White