The Class D51 (D51形) is a type of 2-8-2 steam locomotive operated by the Japanese Government Railways (JGR) and later by the Japanese National Railways (JNR). Designed by JGR's chief mechanical engineer Hideo Shima, they were built by Kawasaki Heavy Industries Rolling Stock Company, Kisha Seizo, Hitachi, Nippon Sharyo, Mitsubishi Heavy Industries and JGR's factories from 1936 to 1945.