Scooby-Doo and the Alien Invaders is a 2000 American direct-to-video animated science fiction romantic comedy mystery film. It is the third direct-to-video film based on Scooby-Doo Saturday morning cartoons. The film was produced by Warner Bros. Animation in association with Hanna-Barbera. It is the third of the first four Scooby-Doo direct-to-video films to be animated overseas by Japanese animation studio Mook Animation. Unlike the previous films and despite the grimmer atmosphere, it has a lighter tone since it's real monsters that are on Mystery Inc.'s side and the disguised human beings are the main villains.

It is the last film to feature Mary Kay Bergman as the voice of Daphne, following her death in November 1999; this film is dedicated in her memory. It is also the last film to use cel animation, as starting with Scooby-Doo and the Cyber Chase the films would later use digital ink and paint.