The Day Mars Invaded Earth (a.k.a. Spaceraid 63) 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.

The film's storyline is a cross between George Pal's The War of the Worlds (1953), and Don Siegel's Invasion of the Body Snatchers (1956). Martian energy beings duplicate a scientist and his family as a first step toward their invasion of Earth to stop humanity's space programs.

The Day Mars Invaded Earth was released as the bottom half of a double feature with the Elvis Presley film Kissin' Cousins.