An EMD SD38AC is a 6-axle diesel-electric locomotive built by General Motors Electro-Motive Division between June and October 1971.

It produces 2,000 horsepower (1,500 kW) from a 16-cylinder EMD 645E roots blown prime mover.

This locomotive shares a common frame with the SD38, SD39, SD40 and SD45.

15 examples of this model were built; 6 for B&LE, 8 for DMIR and one for BC Hydro.

This diesel locomotive-related article is a stub.