The EMD SD45-2 is a 6-axle diesel-electric locomotive built by General Motors Electro-Motive Division (EMD). EMD built 136 locomotives between 1972 and 1974, primarily for the Atchison, Topeka and Santa Fe Railway (ATSF). The SD45-2 was an improved version of the EMD SD45; the primary visual difference is the absence of flared radiators on the SD45-2.

The SD45 is a six-axle diesel-electric locomotive class built by General Motors Electro-Motive Division between 1965 and 1971. It has an EMD 645E3 twenty-cylinder engine generating 3,600 hp (2,680 kW) on the same frame as the SD38, SD39, SD40, and SDP40. As of 2023, most SD45s have been retired, scrapped or rebuilt to SD40-2 standards.