The Sky Crawlers (スカイ・クロラ, Sukai Kurora) is a Japanese novel series by Hiroshi Mori. First published by Chuōkōron-shinsha in June 2001 and spanning five books, it follows the journeys and tribulations of a group of young fighter pilots involved in dogfight warfare, and is set during an alternate historical period. The series is unlike other works by Mori, noted for his series of mystery novels. The art for the series is illustrated by mangaka Kenji Tsuruta. In 2008, the series was adapted into an animated film, directed by acclaimed director Mamoru Oshii.

The first book written and published, but meant to be the last in the series, was The Sky Crawlers, first released in June 2001. A shinshobon (refurbished) edition of the book followed on October 2002, while the bunkobon (paper back) edition followed on October 2004.

The first book, chronologically, in the series, None But Air (ナ・バ・テア, Na Ba Tea), was released in June 2004, while the shinshobon edition for this volume followed on October 2004 and the bunkobon edition followed on November 2005. The second book in the series, Down to Heaven (ダウン・ツ・ヘヴン, Daun Tsu Hevun), followed in June 2005, while its shinshobon edition followed on December 2005 and its bunkobon edition followed on November 2006.

The third book in the series, Flutter into Life (フラッタ・リンツ・ライフ, Furatta Rintsu Raifu), followed in June 2006. The fourth book in the series, Cradle the Sky (クレィドゥ・ザ・スカイ, Kureidu Za Sukai), was released on June 25, 2007, while the fifth book was released in 2008.

The misplaced publishing order was intended to show there is no need to read the story in the chronological order.

The novel was adapted into an anime film, directed by Mamoru Oshii, which was released across Japanese theatres by Warner Bros. Japan on August 2, 2008. Animated by Production I.G, the film was written by Chihiro Itō, features character designs by Tetsuya Nishio and music by Kenji Kawai. The 3D CG animation for the series was produced by the Polygon Pictures studio, who also produced the 3D CG for Oshii's previous film Innocence: Ghost in the Shell.

The series' creator Mori had stated that he felt The Sky Crawlers was the "most difficult" of his works to adapt, and had given his consent to the making of the film after learning of Oshii's involvement as director.

The film will be distributed internationally by Sony Pictures, who announced the release on the film's North American premiere at the 2008 Toronto Film Festival. Sony Pictures had sent this film as their entry for Best Animated Feature at the 81st Academy Awards.

The Sky Crawlers features characters called Kildren (キルドレ, Kirudore) that are humanoids genetically designed to live eternally in adolescence until shot down in an air battle or an "Air Show" to be presented commercially as a peacetime entertainment, for which they are reproduced.

- From Wikipedia