Project ARMS, simply known in Japan as ARMS, is a Japanese manga series written by Kyoichi Nanatsuki and illustrated by Ryoji Minagawa. It was serialized in Shogakukan's Weekly Shōnen Sunday from March 1997 to April 2002, with its chapters collected in 22 tankōbon volumes. The story follows Ryo Takatsuki, who gets involved in an accident when in kindergarten, horribly damaging his arm, but the doctors somehow manage to save it. Several years later, his arm turns out to be more than a normal arm.

It was adapted into a 52-episode anime television series produced by TMS Entertainment and broadcast on TV Tokyo from April 2001 to March 2002. In North America, both the manga and the anime series were licensed by Viz Media. The anime was re-licensed by Discotek Media in 2017.

The manga has had over 15 million copies in circulation. In 1999, Project ARMS received the 44th Shogakukan Manga Award for the shōnen category.