The 717 series (717系) was a Japanese AC electric multiple unit (EMU) train type first introduced by Japanese National Railways (JNR) in March 1985 and later operated on local services by the East Japan Railway Company (JR East) and Kyushu Railway Company (JR Kyushu). The units were formed by converting former AC/DC dual-voltage 451 series, 453 series, 457 series, and 475 series EMUs.