The EMD GP18 is a 4-axle diesel-electric locomotive built by General Motors, Electro-Motive Division between December 1959 and November 1963. Power was provided by a 16-567D1 16-cylinder engine which generated . Additionally, the GP18 had 50 more horsepower than the GP9, for a total of 1,800 horsepower. The new "18" model number was chosen by EMD to reflect the unit's upgraded horsepower rating.

GP18s could be customized by their buyers: railroads ordered GP18s with either high or low short hoods, with or without dynamic brakes, and in the case of Grand Trunk Western, with the optional addition of steam generators.