- Boris Karloff
- Valdar
- Margaret Lindsay
- Helene von Lorbeer - aka Frances Hautry
- Bruce Lester
- Frank Bennett
- Leonard Mudie
- Col. James Yeats
- Holmes Herbert
- Arthur Bennett
- Austin Fairman
- George Bennett
- William Bailey
- British Intelligence Agent
- Louise Brien
- Miss Risdon - Bennett's Secretary
- Glen Cavender
- Under Officer Pfalz
- David Cavendish
- Capt. Lanark
- Joe De Stefani
- German Officer
- Carlos De Valdez
- Von Ritter
- Clarence Derwent
- Milkman
- Arno Frey
- German Junior Officer
- Frederick Giermann
- Otto Kurtz
- Lawrence Grant
- Brigadier General
- Carl Harbaugh
- German Soldier
- Sam Harris
- Cabinet Minister
- Winifred Harris
- Mrs. Maude Bennett
- Leyland Hodgson
- Lord Sudbury
- Stuart Holmes
- Luchow - German Soldier
- Willy Kaufman
- German Corporal
- Crauford Kent
- Cmdr. Phelps
- Morton Lowry
- Lt. Borden
- Lester Matthews
- Henry Thompson
- Frank Mayo
- Brixton - Intelligence Agent
- Paul Panzer
- Peasant
- John J. Richardson
- Cockney Soldier
- Ferdinand Schumann-Heink
- German Officer
- Hans Schumm
- German Senior Officer
- John Graham Spacey
- Crichton - Intelligence Agent
- Robert R. Stephenson
- Cockney Soldier
- Evan Thomas
- Maj. Andrews
- David Thursby
- Agent Reporting Strengler's Identity
- Frederik Vogeding
- Baron Kuglar
- Leonard Willey
- Capt. Stuart
- Maris Wrixon
- Dorothy Bennett
- Henry Zynda
- German
