The 815 series (815系, 815-kei) is an AC electric multiple unit (EMU) train type operated on local services by Kyushu Railway Company (JR Kyushu) in Japan since 1999.

[1] The 815 series was the first aluminium-alloy EMU to be ordered by JR Kyushu, and was designed to be lighter than the earlier 813 series design.

The trains were introduced on wanman driver only operation services, replacing ageing 423, 457, and 475 series rolling stock.

[2] A total of 26 2-car sets (52 cars) were delivered to Kumamoto and Ōita depots between May and October 1999.

[3] The KuMoHa 815 car is fitted with a PS401K single-arm pantograph.