William Powell

Lt. William 'Bill' Gordon / Anson Meridan

Rosalind Russell

Joel Carter

Binnie Barnes

Olivia Karloff

Lionel Atwill

Maj. William Brennan

Cesar Romero

Capt. Nicholas 'Nikki' Nieterstein

Samuel S. Hinds

John Carter, Assistant Secretary of War

Henry Stephenson

Russian Ambassador Gregory

Frank Reicher

Dr. R.A. Jackson

Charley Grapewin

Prof. Martin

Leonard Mudie

Roberts

Howard Hickman

G-Man

Charles Trowbridge

Secretary of War Baker

Murray Kinnell

de Segroff

Margaret Dumont

Mrs. Hendricks (uncredited)

Mary Forbes

Lady Cavendish (uncredited)

Tom Dugan

Agent Patrick O'Reilly (uncredited)

Bernadene Hayes

Bobbie Burns (uncredited)

Winter Hall

Chaplain (uncredited)

Hedwiga Reicher

De Segroff's Associate (uncredited)

Milburn Stone

Carter's Aide (uncredited)