- Edward G. Robinson
- Edward Renard
- Francis Lederer
- Kurt Schneider
- George Sanders
- Franz Schlager
- Paul Lukas
- Dr. Karl F. Kassell
- Henry O'Neill
- Attorney Kellogg
- Dorothy Tree
- Hilda Kleinhauer
- Lya Lys
- Erika Wolf
- Grace Stafford
- Mrs. Schneider
- James Stephenson
- British Military Intelligence Agent
- Hedwiga Reicher
- Mrs. Liza Kassell
- Joe Sawyer
- Werner Renz
- Sig Ruman
- Dr. Julius Gustav Krogman
- Lionel Royce
- Hintze
- Henry Victor
- Wildebrandt
- Hans Heinrich von Twardowski
- Max Helldorf
- Wolfgang Zilzer
- Johann Westphal
- Frederik Vogeding
- Captain Richter
- Willy Kaufman
- Greutzwald
- Rudolph Anders
- Captain Straubel
- Wilhelm von Brincken
- Captain von Eichen
- George Rosener
- Klauber
- Frederick Burton
- U.S. District Court Judge
- Eily Malyon
- Mrs. Mary McLaughlin
- Bodil Rosing
- Anna Keller - Passenger on Boat
- John Deering
- Narrator
- Louis Adlon
- Nazi American Youth Leader
- Fred Aldrich
- Nazi at Bund Meeting
- Sherwood Bailey
- Newsboy at End
- Ward Bond
- American Legionnaire
- Walter Bonn
- Naval Officer Seeing Renard at Seaplane
- Egon Brecher
- Fritz Muller - German Agent
- Tommy Bupp
- Shoeshine Boy
- Glen Cavender
- Man in Montage Stuffing Mailboxes
- John Conte
- Radio Announcer
- Alec Craig
- McGregor - Scottish Postman
- Jimmie Dundee
- Nazi Goon at Bund Meeting
- Jack Egger
- Undetermined Secondary Role
- Frederick Giermann
- German-American at Bund Meeting
- Lisa Golm
- Mrs. Anna Westphal
- Sol Gorss
- Nazi Goon at Bund Meeting
- William Gould
- FBI Agent
- Fred Graham
- American Legionnaire at Bund Meeting
- Creighton Hale
- Draftsman
- John Hamilton
- FBI Chief
- John Harron
- Man in Montage with Propaganda
- Eddie Hart
- Nazi Agent
- Adolf Hitler
- Self
- Max Hoffman Jr.
- Soldier at Renz's Arrest
- Stuart Holmes
- Draftsman
- Arthur Stuart Hull
- U.S. Government Agent
- Selmer Jackson
- Customs Official
- Edward Keane
- FBI Agent
- Robert Emmett Keane
- Harrison - Passport Official
- Milton Kibbee
- Man Greeting Waiter Bill
- Martin Kosleck
- Joseph Goebbels
- Jack Low
- Nazi at Meeting
- Frank Mayo
- FBI Agent Phillips
- Lon McCallister
- Undetermined Secondary Role
- Ray Miller
- Bill - Coffee Shop Proprietor
- Walter Miller
- Bill - Waiter with Coffee
- Jack Mower
- FBI Agent 'Mac' MacDonald
- George Offerman Jr.
- Western Union Messenger
- Lotte Palfi Andor
- Kassel's Nurse
- Steve Pendleton
- Naval Courier
- Gil Perkins
- Goebbels' Aide
- Norman Phillips Jr.
- Gottfried Simmons - Nazi Youth
- Tempe Pigott
- Undetermined Secondary Role
- Lucien Prival
- Kranz
- Otto Reichow
- Driver of Nazi Car That Crashed
- John Ridgely
- Army Hospital Clerk
- Ferdinand Schumann-Heink
- Undetermined Secondary Role
- Hans Schumm
- Bismarck Officer with Crew List
- Lester Sharpe
- Undetermined Secondary Role
- Charles Sherlock
- FBI Agent Fred Young
- Edwin Stanley
- U.S. Official
- Rudolf Steinboeck
- Undetermined Secondary Role
- Robert R. Stephenson
- Fritz - von Eichen's Aide
- Regis Toomey
- Tom - in Coffee Shop
- Frederic Tozere
- FBI Agent Staunton
- Charles Trowbridge
- Maj. Williams
- Emmett Vogan
- Hotel Desk Clerk
- Dave Wengren
- Undetermined Secondary Role
