Koki Oshima (大島 康樹, born 30 May 1996 in Shizuoka, Japan) is a Japanese footballer who plays for Ventforet Kofu.
Oshima made his official debut for Kashiwa Reysol in the J. League Division 1, J. League Cup on 9 October 2014 against Sanfrecce Hiroshima in Hiroshima Big Arch in Hiroshima, Japan. In the 72nd minute Oshima subbed in for Leandro. Oshima and his club lost the match 2-0.
Updated to 23 February 2018.