Keisuke Itagaki (born April 4, 1957) is a Japanese manga artist. He is best known for his martial arts series Grappler Baki (1991–1999) and its four sequels, which have sold over 75 million volumes. In 1996, he began working on Garōden, an original work by Baku Yumemakura. He has also collaborated on the series Garōden Boy.
Prior to becoming a manga artist, he served 5 years in the 1st Airborne Brigade of the Japan Ground Self-Defense Force. During his service, he practiced amateur boxing and has competed in the National Sports Festival. He also holds a degree in Shorinji Kempo, which he has practiced since he was a teenager.