The Class DD15 (DD15形) is a four-axle Bo-Bo wheel arrangement diesel-hydraulic locomotive type operated in Japan as a self-propelled snowplough unit since 1961 by the national railway company Japanese National Railways (JNR), and later by East Japan Railway Company (JR East) and West Japan Railway Company (JR West).

[1] The snowplough units could be detached, allowing the locomotives to be used for shunting and other duties outside the winter periods.

[1] However, with the snowplough units mounted, the locomotive axle load was nearly 16 t, restricting use on rural lines, and so the class was superseded by the later Class DE15 locomotives, which had separate snowplough units.

[2] At the time of privatization of Japanese National Railways (JNR) on 1 April 1987, 32 Class DD15 locomotives remained in service, with JR East receiving 19 and JR West receiving 13.

[1] As of 1 April 2016[update], six locomotives remain in service, all operated by JR West.