Kobayashi's bat (Eptesicus kobayashii) is a species of bat. An adult Kobayashi's bat has a body length of 6–, a tail length of 4.6–, and a wing length of 4.5–. The species is found only on the Korean Peninsula; it has been suggested that it may be a local form of Eptesicus bottae, Botta's serotine.