Generator Rex is an American animated science fiction television series created by Man of Action for Cartoon Network, with John Fang of Cartoon Network Studios as supervising director. It was inspired by the comic M. Rex, created by Aaron Sowd, Joe Kelly and Duncan Rouleau, and published by Image Comics in 1999. The series premiered in the United States on April 23, 2010, on Cartoon Network, and concluded on January 3, 2013, with a total of 60 episodes, plus two episodes remained unaired.

A two-part crossover special with Ben 10: Ultimate Alien, titled Ben 10/Generator Rex: Heroes United, aired on November 25, 2011, while a second 44-minute four-part special, Ben Gen 10, aired on April 11, 2021, featuring different and younger versions of the Generator Rex characters in the Ben 10 universe.