The GP20D is a four-axle B-B switcher locomotive built by MotivePower and Electro-Motive Diesel.

It was supplied with a Caterpillar 3516 (called a 16-170B20-T2 by EMD) V16 prime mover which develops a total power output of 2,000 horsepower (1,490 kW).

To date, only 40 units have been produced by EMD, all of which were manufactured during June 2000.

The changes between the MK2000D and the GP20D are primarily in the control electronics, making them easier to use than the older model.

The similar appearing EMD GP15D does not have dynamic brakes and has a lower horsepower rating (1500 vs 2000).