Seiji Kobayashi (小林 誠司, born June 7, 1989) is a Japanese professional baseball catcher for the Yomiuri Giants of Nippon Professional Baseball (NPB).

Kobayashi attended Doshisha University, where he played for the school's baseball team.

The Yomiuri Giants selected Kobayashi in the 2013 Nippon Professional Baseball draft.

[2] Kobayashi represented the Japan national baseball team in the 2014 MLB Japan All-Star Series, 2015 exhibition games against Europe, 2017 World Baseball Classic, 2019 exhibition games against Mexico and 2019 WBSC Premier12.

This biographical article relating to a Japanese baseball catcher is a stub.