Xenosaga: The Animation (Japanese: ゼノサーガ THE ANIMATION, Hepburn: Zenosāga: Za Animēshon) is a mecha anime produced by Toei Animation. The 12-episode series ran from January to March 2005 on TV Asahi, while it was licensed for release on DVD overseas first by A.D. Vision and later by Funimation Entertainment. The anime is based on the narrative of Xenosaga Episode I, a role-playing game for the PlayStation 2 developed by Monolith Soft and published by Namco. Set 5000 years in the future, it tells of the adventures of scientist Shion Uzuki and the battle android KOS-MOS as they fight the threat of the alien Gnosis.

The anime was created mostly without the involvement of Namco following the success of the first game, though any new characters were created with Namco's permission. The characters were redrawn for the anime by Nobuteru Yūki, while the script was written by Yuichiro Takeda. The music, composed by Kousuke Yamashita, was designed to emulate the original game's orchestral score. The anime has received mixed to positive reviews from journalists, with many commenting that only those familiar in the game would understand it. Both Yamashita and Takeda were later involved in the production of Xenosaga I & II, a Nintendo DS re-imagining of the first game and its direct sequel.