Buso Renkin (Japanese: 武装錬金, Hepburn: Busō Renkin, lit. transl. "Alchemical Weapons") is a Japanese manga series written and illustrated by Nobuhiro Watsuki. It follows Kazuki Muto, who becomes an alchemical warrior in the battle against alchemical monsters known as homunculi. Watsuki envisioned the manga as his last shōnen manga, and then he tried to do as much as he could with that genre. It was serialized in publisher Shueisha's Weekly Shōnen Jump magazine from June 2003 to April 2005. The individual chapters were republished by Shueisha in ten tankōbon (bound volumes). The series has been licensed by Viz Media for North American release.

The manga has been adapted into an anime television series, which was produced by studio Xebec and was broadcast on Japanese television network TV Tokyo from 2006 to 2007. In December 2007, the anime was announced for North American DVD release by Viz Media. In 2009, the series made its American television debut on the Funimation Channel, with American broadcast rights acquired by Funimation from Viz Media. The series has also spawned two drama CDs, two light novels, a PlayStation 2 video game, and many types of Buso Renkin-themed merchandise.

In Japan, the Buso Renkin manga has sold over 3 million volumes and was nominated for the science fiction works focused Seiun Award. It received a mixed reception from Western manga and anime publications. Watsuki's art received the most positive comments from reviewers, while other aspects of the manga, such as its action and characters, have divided critics' opinions. The anime, which critics described as a generic shōnen fighting series, received mostly negative reception.