The KuMoHa 12 (クモハ12形) was a class of electric multiple unit (EMU) railroad cars formerly used by the Japanese National Railways (JNR).

These are EMU power cars of 17-meter (56 ft) length with a driver's cab at each end, three passenger doors on each side, and lengthwise bench-type passenger seating.

The cars themselves were built in the later 1920s and 1930s for JNR's predecessor, the Japanese Government Railways (JGR), but the class, originally named MoHa 12 (モハ12形), was established on 1 June 1953 by a JNR revision of its rolling stock classification regulations.

In June 1959, a new JNR classification revision assigned the code KuMo (クモ) to all cab-equipped power cars, giving the KuMoHa 12 class its present name.

Over time, additional cars were added by remodeling related old JGR classes, for an eventual total of 33 cars.