The 105 series (105系, 105-kei) is a DC electric multiple unit (EMU) train type formerly operated by Japanese National Railways (JNR), and currently operated on local services by West Japan Railway Company (JR West) in Japan since 1981.

The rural nature and low line speed of these lines meant that 101 series or 103 series commuter EMUs would have been unnecessarily over-powered with their high proportion of motored cars, and so the 105 series was designed with one motored car per two cars.

[1] As of 1 April 2012, 56 2-car sets are operated by JR-West, based at Hineno, Okayama, Shimonoseki, and Hiroshima depots.

[2] The 105-500/600 series variant was introduced from October 1984, coinciding with the electrification of the Nara Line between Kyoto and Nara, and the Wakayama Line between Wakayama and Gojō.

These sets retained the original non-gangwayed 103 series cab ends.