Brotherhood: Final Fantasy XV (Japanese: ブラザーフッド ファイナルファンタジーXV, Hepburn: Burazāfuddo: Fainaru Fantajī Fifutīn) is an original net animation series directed by Soichi Masui, produced by Akio Ofuji, written by Yuniko Ayana, and composed for by Yasuhisa Inoue and Susumi Akizuki. Co-produced by Square Enix and A-1 Pictures, it is based on the setting and story of the 2016 video game Final Fantasy XV, which is thematically connected to the Fabula Nova Crystallis subseries. Brotherhood is set within the events of Final Fantasy XV, and details the backstories of main protagonist Noctis Lucis Caelum and those closest to him.

Brotherhood was made as part of a planned multimedia expansion of Final Fantasy XV without the need to develop a series of games. The series was conceived by Ofuji in 2014, based on his wish to expand upon an in-game reference to the difficult childhood of one of the characters. The story focuses on themes of brotherhood and friendship, and was designed to give players glimpses into the personal lives and personalities of the characters that would not have fitted within the game.

The series ran from March 30 to September 17, 2016. Streaming free online through YouTube and Crunchyroll, the series was bundled with different editions of Final Fantasy XV, alongside fellow spin-off title Kingsglaive: Final Fantasy XV. The Ultimate Collector's Edition of the game included additional scenes focusing on the character Lunafreya Nox Fleuret. The episodes were among the most popular videos on the game's official YouTube channel, and opinions on the anime have been generally positive.