The Day Mars Invaded Earth is an independently made 1963 black-and-white CinemaScope science fiction film, produced and directed by Maury Dexter, that stars Kent Taylor, Marie Windsor, and William Mims. The film was released by Twentieth Century Fox. Dexter later said the film's title came from Associated Producers' Robert L. Lippert and was meant to evoke memories of Fox's 1951 classic The Day the Earth Stood Still.

Marie Windsor was an American actress known for her femme fatale characters in the classic film noir features Force of Evil, The Narrow Margin and The Killing. Windsor's height created problems for her in scenes with all but the tallest actors. She was the female lead in so many B movies that she became dubbed the "Queen" of the genre.