Clone High is an adult animated science fiction sitcom created by Phil Lord, Christopher Miller, and Bill Lawrence for MTV. It premiered on November 2, 2002, in Canada, and January 20, 2003, in the United States. Set at a high school populated by the clones of well-known historical figures, the series follows its central cast which includes adolescent depictions of Abe Lincoln, Joan of Arc, Gandhi, Cleopatra and JFK. The series also serves as a parody of teen dramas such as Dawson's Creek, Degrassi, and Beverly Hills, 90210; every episode is humorously introduced as a "very special episode" with narration provided by Will Forte.

Lord and Miller first developed the series' concept, originally titled Clone High School, USA!, while at Dartmouth College in the 1990s, later pitching it to executives of the Fox Broadcasting Company during their tenure at Disney, who ultimately decided to pass on the program. The rights were purchased by Viacom International to air on their cable channel MTV, producing the series between 2002 and 2003; Disney's television arm Touchstone Television retains a production credit. The show's design is heavily stylized and its animation style is limited, emphasizing humor and story over visuals. The Clone High theme song, "Master (Clone High Theme)", was written by Tommy Walter and performed by his alternative rock band Abandoned Pools. The series was produced by Bill Lawrence, who also produced Scrubs, Spin City and Cougar Town. Many Scrubs alumni, such as Zach Braff, Donald Faison, Sarah Chalke, John C. McGinley, Neil Flynn, and Christa Miller, provided the voices of characters in Clone High for free, with Flynn also reprising his role from Scrubs as the Janitor (Glenn) in a recurring role. Writing and voice work were done at North Hollywood Medical Center, where Scrubs was filmed.

The first season premiered on Canadian cable channel Teletoon's late-night programming block The Detour on Teletoon on November 2, 2002, and MTV in the United States on January 20, 2003. It became embroiled in controversy regarding its depiction of Gandhi soon afterward, which prompted over 100 people in India to mount a hunger strike in response. Shortly after, MTV canceled the series, which had been receiving low ratings; the last episodes of the first season were seen in 2016 on MTV Classic in the United States. Clone High received mixed reviews from television critics upon its premiere, but it has since received critical acclaim and a cult following.

On July 2, 2020, it was announced that a revival of the series was in development at MTV Entertainment Studios with the creators Lord, Miller, and Lawrence returning. On February 10, 2021, it was announced that HBO Max had ordered two seasons of the revival, which premiered on May 23, 2023. The second season of the revival (third season overall) premiered with all ten episodes on February 1, 2024. On July 26, 2024, the revival of the series was canceled after two seasons, leaving the series on another cliffhanger.