Masaki Kyomoto (京本政樹, Kyōmoto Masaki, January 21, 1959 –) is a Japanese actor, singer-song writer, and guitarist. He is famous for playing the role of Ryu on the television jidaigeki Hissatsu series.

He has appeared in films and television series including Legend of the Eight Samurai, Sukeban Deka, Kamen Rider Black,Kamen Rider Agito, Ultraman: Towards the Future (aka Ultraman Great), Cutie Honey, Chage and Aska, Ōedo Sōsamō, Mito Kōmon, Anmitsu Hime, Food Fight, Ultraman Tiga, Ultraman Dyna, Ii Hito, GARO, Tenchu:Yamino Shiokinin and most recently 81diver. He has performed on the soundtracks to GARO and Garo Special: Byakuya no Maju, performing the first two ending themes for the former, and producing GARO Project's performances of the final two ending themes for the series and the ending theme for the special.

Masaki got a role in a buster film Legend of the Eight Samurai as Inuzuka Shino and it became a sensation that lead to Masaki's break out role "Ryu" on a popular Japanese period piece samurai drama series Hissatsu Shigotonin where he played Japanese obi-belt maker who is ex-ninja turned to be an assassin (shigotonin) to kill bad guys. He became a big star by that role and since then has appeared in numerous period piece drama series. He often plays a role much younger than his actual age due to youthful appearance. His picture with his son Taiga Kyomoto (SixTONES) went viral in Asia and many thought he is Taiga's older brother instead of father. He is an established musician as well produced sound track for TV shows and music for himself and other singers.