Fist of the Blue Sky (Japanese: 蒼天の拳, Hepburn: Sōten no Ken) is a Japanese manga series written and illustrated by Tetsuo Hara, with plot supervision by Buronson. It was serialized in Weekly Comic Bunch from 2001 to 2010, with the chapters collected into 22 tankōbon volumes by Shinchosha. It is a prequel to the popular 1980s manga Fist of the North Star, which Hara originally illustrated with Buronson writing. Set primarily in Shanghai during the 1930s, the series centers on the 62nd successor of the Hokuto Shinken martial arts style, Kenshiro Kasumi, the namesake and predecessor of Kenshiro from Fist of the North Star. The manga was adapted into a 26-episode anime series that aired on TV Asahi from 2006 to 2007.

A continuation of the manga, titled Sōten no Ken: Re:Genesis (蒼天の拳 RE:GENESIS), began serialization in the December 2017 issue of Comic Zenon. It is written by Hiroyuki Yatsu and illustrated by Hideki Tsuji with the additional involvement of Tetsuo Hara. An anime series of the same name began airing from April 2 to December 17, 2018 with oversight by Tetsuo Hara.