Billy: The Movie is a 2005 American animated musical film created by Maxwell Atoms. It based on the Cartoon Network TV Series "The Grim Adventures of Billy & Mandy".
- Richard Steven Horvitz as Billy
- Greg Eagles as Grim Reaper
- Grey DeLisle as Mandy
- Professor Utonium as a citizen.
- Blu from Foster's Home for Imaginary Friends as one of the ghosts.
- Raj from Camp Lazlo is seen on the zoo.
- Bubbles, Blossom and Buttercup is seen on a poster.
- Chowder as one of the Billy's toys.
- Fred Flintstone as one of Billy's buddies.
- The Grim Adventures of Billy & Mandy theme (movie version)
- Star Wars theme