Rudolph Anders
Acting
Spy Smasher Returns
Col. Von Kahr
The Prize
Mr. Rolfe Bergh - Chaperon
Decision at Midnight
The Pigeon That Took Rome
Col. Wilhelm Krafft
On the Double
Oberkommandant
A Private's Affair
Dr. Leyden
Frankenstein 1970
Wilhelm Gottfried
She Demons
Col. Karl Osler
The Snow Creature
Dr. Louis DuPont
A Star Is Born
Mr. Ettinger (uncredited)
Jungle Gents
Dr. Goebbel
King Richard and the Crusaders
Austrian Knight (uncredited)
Magnificent Obsession
Dr. Albert Fuss
Silver Needle in the Sky
Dr. Loran
Captain Scarface
Dr. Yeager
South Sea Woman
Capt. van Dorck
Phantom from Space
Dr. Wyatt
Target Unknown
Doctor (uncredited)
Kill or Be Killed
Gregory Marek
Act of Violence
German (voice) (uncredited)
Dangerous Millions
Rudolph Busch
Under Nevada Skies
Alberti
Escape in the Desert
Hoffman
Counter-Attack
Stillman
Sherlock Holmes and the Secret Weapon
Braun (uncredited)
The Great Impersonation
Karl Hofmann
Junior Army
Horner - Nazi Saboteur (as Robert O. Davis)
The Devil with Hitler
Nazi Officer at Hitler's filmed Speech (uncredited)
Desperate Journey
Kruse
The Secret Code
Rudi Thysson
The Pied Piper
Lieutenant
Riders of the Northland
Agent (as Robert O. Davis)
Eagle Squadron
German Squad Leader
The Phantom Plainsmen
Colonel Eric Hartwig (as Robert O. Davis)
Spy Smasher
Col. Von Kohr
To Be or Not to Be
Gestapo Sergeant at Desk at Top of Hotel Stairs (uncredited)
Nazi Agent
Cab Driver (uncredited)
King of the Texas Rangers
His Excellency
A Dangerous Game
Dr. Fleming
Down in San Diego
Henry Schrode
Underground
Official
Mr. Dynamite
Frederick the Butler
Arise, My Love
Prussian Officer (uncredited)
Meet the Wildcat
Feral--Henchman
The Great Dictator
Tomanian Commandant at Osterlich / Robert O. Davis
Knute Rockne All American
Elder in Norway (uncredited)
The Man I Married
Storm Trooper
The Mortal Storm
Gestapo Official Hartman
Escape to Paradise
Alexander Komac
The Mad Empress
Herzfeld
Pack Up Your Troubles
Von Richtman
Espionage Agent
Paul Strawn (as Robert O. Davis)
Confessions of a Nazi Spy
Captain Straubel
That Mothers Might Live
Doctor (uncredited)
Champagne Waltz
Emperor Franz Joseph
We're in the Legion Now
Sgt. Groeber
Last of the Pagans
Superintendant's Assistant (uncredited)
Rendezvous
Radio Operator (uncredited)
Here's to Romance
Violinist
Hell in the Heavens
Lt. Schroeder (as Rudolph Amendt)
The Fountain
Geof Van Leyden
Stamboul Quest
Karl (as Rudolph Amendt)