Shotaro Onishi

 is a former Japanese rugby union player who played as a centre. He spent his whole career playing for both Kintetsu Liners and Toyota Industries Shuttles in Japan's domestic Top League, playing over 560 times. He was named in the Japan squad for the 2007 Rugby World Cup, making 3 appearances in the tournament. He made a further 30 appearances for Japan in his career, scoring 71 points.