Onishi Ken'ya (大西 研也, born July 27, 1995) is a Nihon Ki-in professional player.
1p: 2012, 2p: 2014-02-01, 3p: 2016-11-25, 4p: 2019-07-29 (50 wins)
Quarterfinalist in the 42nd (2017) Shinjin O, runner up in the 43rd (2018) and semifinalist in the 44th (2019).
Kenya won his group in the initial preliminaries of the 47th (2022) Meijin, beating Ishida Yoshio and Uchida Shuhei. However, he failed to make it through the second stage, being eliminated by Mimura Tomoyasu.