The initial working draft screenplay of Citizen Kane, dated April 16, 1940, was titled American.

After Susan attempts suicide, Kane releases her from her disastrous operatic career and retires to Xanadu.

For the scene in which Kane and his entourage visit the beach, the large birds flying in the background are actually previously created footage of pterodactyls from either King Kong (1933) or Son of Kong (1933).

It was widely believed the film would win most of its nine Oscar nominations, but it took only the award for Best Writing (Original Screenplay), shared by Welles and Mankiewicz. Variety reported that block voting by screen extras deprived Citizen Kane of Academy Awards for Best Picture and Best Actor (Welles).

Orson Welles was just 25 years old when he directed, co-wrote, starred in and produced the film, his very first feature.

The opening scene, in which a dying Kane whispers the pivotal line of "Rosebud," was shot in one take.