Ben 10 (retroactively known as Classic Ben 10) is an American animated series created by Man of Action, produced by Cartoon Network Studios and distributed by Warner Bros. Domestic Television. The series is about a 10-year-old boy named Ben Tennyson who gets a watch-style alien device called the "Omnitrix". Attached to his wrist, it allows him to transform into 10 different alien creatures with different abilities, allowing him to fight evil from Earth and space with his cousin Gwen and grandfather Max. The series first aired on Cartoon Network as a sneak peek on December 27, 2005, as part of "Sneak Peek Week", airing alongside other shows, including My Gym Partner's a Monkey, Robotboy and Zixx. It later became a full series airing from January 13, 2006, to April 15, 2008.

The series gradually became popular and was nominated for two Emmy Awards, winning one for "Outstanding Individual Achievement in Animation". The show spawned a franchise: three continuations were released respectively as Ben 10: Alien Force, Ben 10: Ultimate Alien and Ben 10: Omniverse; as well as a reboot of the series in 2016.