 Spy Smasher Returns1966 · Col. Von Kahr | Col. Von Kahr |
 The Prize1963 · Mr. Rolfe Bergh - Chaperon | Mr. Rolfe Bergh - Chaperon |
 Decision at Midnight1963 · Uncle | Uncle |
 The Pigeon That Took Rome1962 · Col. Wilhelm Krafft | Col. Wilhelm Krafft |
 On the Double1961 · Oberkommandant | Oberkommandant |
 A Private's Affair1959 · Dr. Leyden | Dr. Leyden |
 Frankenstein 19701958 · Wilhelm Gottfried | Wilhelm Gottfried |
 She Demons1958 · Col. Karl Osler | Col. Karl Osler |
 The Snow Creature1954 · Dr. Louis DuPont | Dr. Louis DuPont |
 A Star Is Born1954 · Mr. Ettinger (uncredited) | Mr. Ettinger (uncredited) |
 Jungle Gents1954 · Dr. Goebbel | Dr. Goebbel |
 Magnificent Obsession1954 · Dr. Albert Fuss | Dr. Albert Fuss |
 King Richard and the Crusaders1954 · Austrian Knight (uncredited) | Austrian Knight (uncredited) |
 Silver Needle in the Sky1954 · Dr. Loran | Dr. Loran |
 Captain Scarface1953 · Dr. Yeager | Dr. Yeager |
 South Sea Woman1953 · Capt. van Dorck | Capt. van Dorck |
 Phantom from Space1953 · Dr. Wyatt | Dr. Wyatt |
 Target Unknown1951 · Doctor (uncredited) | Doctor (uncredited) |
 Kill or Be Killed1950 · Gregory Marek | Gregory Marek |
 Act of Violence1949 · German (voice) (uncredited) | German (voice) (uncredited) |
 Dangerous Millions1946 · Rudolph Busch | Rudolph Busch |
 Under Nevada Skies1946 · Alberti | Alberti |
 Escape in the Desert1945 · Hoffman | Hoffman |
 Counter-Attack1945 · Stillman | Stillman |
 Watch on the Rhine1943 · Oberdorff | Oberdorff |
 Sherlock Holmes and the Secret Weapon1942 · Braun (uncredited) | Braun (uncredited) |
 The Great Impersonation1942 · Karl Hofmann | Karl Hofmann |
 Junior Army1942 · Horner - Nazi Saboteur (as Robert O. Davis) | Horner - Nazi Saboteur (as Robert O. Davis) |
 The Devil with Hitler1942 · Nazi Officer at Hitler's filmed Speech (uncredited) | Nazi Officer at Hitler's filmed Speech (uncredited) |
 Desperate Journey1942 · Kruse | Kruse |
 The Secret Code1942 · Rudi Thysson | Rudi Thysson |
 The Pied Piper1942 · Lieutenant | Lieutenant |
 Riders of the Northland1942 · Agent (as Robert O. Davis) | Agent (as Robert O. Davis) |
 The Phantom Plainsmen1942 · Colonel Eric Hartwig (as Robert O. Davis) | Colonel Eric Hartwig (as Robert O. Davis) |
 Eagle Squadron1942 · German Squad Leader | German Squad Leader |
 Spy Smasher1942 · Col. Von Kohr | Col. Von Kohr |
 To Be or Not to Be1942 · Gestapo Sergeant at Desk at Top of Hotel Stairs (uncredited) | Gestapo Sergeant at Desk at Top of Hotel Stairs (uncredited) |
 Nazi Agent1942 · Cab Driver (uncredited) | Cab Driver (uncredited) |
 King of the Texas Rangers1941 · His Excellency | His Excellency |
 A Dangerous Game1941 · Dr. Fleming | Dr. Fleming |
 Down in San Diego1941 · Henry Schrode | Henry Schrode |
 Underground1941 · Official | Official |
 Mr. Dynamite1941 · Frederick the Butler | Frederick the Butler |
 Arise, My Love1940 · Prussian Officer (uncredited) | Prussian Officer (uncredited) |
 Meet the Wildcat1940 · Feral--Henchman | Feral--Henchman |
 The Great Dictator1940 · Tomanian Commandant at Osterlich / Robert O. Davis | Tomanian Commandant at Osterlich / Robert O. Davis |
 Knute Rockne All American1940 · Elder in Norway (uncredited) | Elder in Norway (uncredited) |
 The Man I Married1940 · Storm Trooper | Storm Trooper |
 The Mortal Storm1940 · Gestapo Official Hartman | Gestapo Official Hartman |
 Escape to Paradise1939 · Alexander Komac | Alexander Komac |
 The Mad Empress1939 · Herzfeld | Herzfeld |
 Pack Up Your Troubles1939 · Von Richtman | Von Richtman |
 Espionage Agent1939 · Paul Strawn (as Robert O. Davis) | Paul Strawn (as Robert O. Davis) |
 Confessions of a Nazi Spy1939 · Captain Straubel | Captain Straubel |
 That Mothers Might Live1938 · Doctor (uncredited) | Doctor (uncredited) |
 Champagne Waltz1937 · Emperor Franz Joseph | Emperor Franz Joseph |
 We're in the Legion Now1936 · Sgt. Groeber | Sgt. Groeber |
 Last of the Pagans1935 · Superintendant's Assistant (uncredited) | Superintendant's Assistant (uncredited) |
 Rendezvous1935 · Radio Operator (uncredited) | Radio Operator (uncredited) |
 Here's to Romance1935 · Violinist | Violinist |
 Hell in the Heavens1934 · Lt. Schroeder (as Rudolph Amendt) | Lt. Schroeder (as Rudolph Amendt) |
 The Fountain1934 · Geof Van Leyden | Geof Van Leyden |
 Stamboul Quest1934 · Karl (as Rudolph Amendt) | Karl (as Rudolph Amendt) |
