Citizen Kane. But it's not a sci-fi movie.
The Wolf Man, circa 1941.
As far as I can find, the first feature film with an elephant was Dumbo in 1941
Golden Gate Girl in 1941. he played an Infant
Sergeant York won the Oscar for Film Editing in 1941.
The first film directed by John Houston was The Maltese Falcon in 1941. Most of his films were adaptations of important novels. He lived from 1906 to 1987.
Intrigue - film - was created in 1941.
Lend a Paw won the Oscar for Short Film - Animated - in 1941.
Comedy
It was written for the 1941 film Dangerous Moonlight
Escort Girl - film - was created in 1941.
Major Barbara - film - was created in 1941.
The Chocolate Soldier - film - was created in 1941.