The GMD GMDH-3 is an experimental diesel-hydraulic switching locomotive built in January 1960 by General Motors Diesel of Canada.

After being built in January 1960, the locomotive served as a demonstrator for GMD, bearing number #275, between 1960 and 1962, during which it spent a period in Egypt, but no sales resulted.

[3] The locomotive was sold in 1963 to McKinnon Industries of St. Catharines, Ontario as their plant switcher, #2128.

[3] After a fund-raising effort, the Southern Michigan Railroad Society purchased the locomotive in 1996, where it remains in operable condition as of 2006[update].

[4] As of June 2015, GMDH-3 had been repainted in two-tone blue, and is still parked in Clinton, Michigan awaiting funds for restoration.