20th Century Boys

20th Century Boys (Japanese: 20世紀少年, Hepburn: Nijusseiki Shōnen) is a Japanese manga series written and illustrated by Naoki Urasawa. It was originally serialized in Shogakukan's seinen manga magazine Big Comic Spirits from 1999 to 2006, with the 249 chapters published into 22 tankōbon volumes. A 16 chapter continuation, titled 21st Century Boys (21世紀少年, Nijūisseiki Shōnen), ran in the same magazine from 2006 to 2007 and was gathered into two tankōbon volumes. It tells the story of Kenji Endo and his friends, who notice that a cult-leader known only as "Friend" is out to destroy the world, and that his cult icon bears a striking resemblance to a symbol developed during their childhoods. The series makes many references to a number of manga and anime from the 1960s–1970s, as well as to classic rock music, its title being taken from T. Rex's song "20th Century Boy".

A trilogy of live-action film adaptations, directed by Yukihiko Tsutsumi, were released in 2008 and 2009. The manga was licensed and released in English by Viz Media, and distributed in Australasia by Madman Entertainment. The films were also licensed by Viz in North America and by 4Digital Media in the United Kingdom.

20th Century Boys has received critical acclaim and has 36 million copies in circulation, making it one of the best-selling manga series of all time. It has won several awards, including the Shogakukan Manga Award, the Kodansha Manga Award and the Seiun Award.