The EMD GP40 is a 4-axle diesel-electric locomotive built by General Motors' Electro-Motive Division between November 1965 and December 1971.

The difference in length can be seen in the GP40's ten handrail stanchions compared to the GP35's nine.

60 units were built with high-short-hoods and dual control stands for Norfolk & Western Railway.

Two passenger versions, the GP40P and GP40TC, were also built, but on longer frames to accommodate steam generators and HEP equipment.

On January 1, 1972, the GP40 was discontinued and replaced by the GP40-2, which has a modular electrical system and a few minor exterior changes.