Electro-Motive Diesel is a brand of diesel-electric locomotives, locomotive products and diesel engines for the rail industry. Formerly a division of General Motors, EMD has been owned by Progress Rail since 2010. Electro-Motive Diesel traces its roots to the Electro-Motive Engineering Corporation, founded in 1922 and purchased by General Motors in 1930. After purchase by GM, the company was known as GM's Electro-Motive Division. In 2005, GM sold EMD to Greenbriar Equity Group and Berkshire Partners, and in 2010, EMD was sold to Progress Rail. Upon the 2005 sale, the company was renamed to Electro-Motive Diesel.

General Motors Company (GM) is an American multinational automotive manufacturing company headquartered in Detroit, Michigan, United States. The company is most known for owning and manufacturing four automobile brands, Chevrolet, GMC, Cadillac and Buick. By sales, it was the largest automaker in the United States in 2022, and was the largest in the world for 77 years before losing the top spot to Toyota in 2008.