- Celebrity Voice Actor: Like most mainstream animated films, Planet 51 has a lot of them, including Dwayne Johnson, Justin Long, Jessica Biel, Seann William Scott, Gary Oldman and John Cleese.
- What Could Have Been: The movie was to be released by New Line in the United States, but when Warner Bros. took over the studio the producers demanded that the film take up Harry Potter and the Half-Blood Prince's former release date. Warner dropped the movie in refusal, and Sony/TriStar then picked up the rights, settling with a November 2009 release date.
- Working Title: Planet One, It was changed due to copyright issues with the Planet One Channel which produces children and teen TV programmes.
Trivia / Planet 51