Australia

• 7 BHP Whyalla DE class

Brazil

A total of 241 locomotives:

• 2 Estrada de Ferro de Goiás 5201–5202
• 30 Mogiana Railway 3001–3030
• 43 Estrada de Ferro Noroeste do Brasil 1101–1143
• 17 Rede de Viação Paraná-Santa Catarina
• 18 Companhia Paulista de Estradas de Ferro 700–717
• 25 Rede Mineira de Viação 2201–2207, 2217–2228
• 71 Viação Férrea do Rio Grande do Sul 2121–2145, 2161–2168, 6169–6206
• 35 Estrada de Ferro Vitória a Minas 531–565

Canada

• 2 London & Port Stanley Railway L4, L5
• 1 General Motors Diesel demonstrator 7707 (to Sweden as Statens Järnvägar T42 in service between 1956 and 1983^[1] preserved by the Swedish State Railroad Museum and is still in running order.^[2])

Chile

• 3 Andes Copper Mining 81–83, currently on service by Ferronor.

Egypt

• 97 Egyptian Railways 3701–3797.^[3] During the 1967 Six-Day War, Israel captured 3712, 3715, 3766 and 3795, which were appropriated to Israel Railways stock.

Israel

• 23 Israel Railways 104–126,^[4] some since rebuilt with 12-645E engines. After the 1967 Six-Day War, four captured Egyptian G12s were renumbered 127–130.^[5]

Iran

• 137 Islamic Republic of Iran Railways 40.01–40.137
• Driver cab of most of the active units have been changed to full view like GT26.
• Railway Research Center (MATRAI) has converted one of G12 loco to Hybrid locomotive in 2001 with AC drive.

Hong Kong

• 5 Kowloon-Canton Railway Corporation No. 51–55
  • 52–55 re-sold to Chicago Freight Car Leasing Australia as TL152–TL155
  • 51 Sir Alexander, named after by-then governor of Hong Kong in 1955, Alexander Grantham, was donated and preserved in Hong Kong Railway Museum after retirement and restoration^[6]

Mexico

• 84 Ferrocarriles Nacionales de México 5806–5889

Netherlands

• 5 Dutch State Mines SM 151-155 (Built in 1956-1959 under license as Henschel G12 in Germany). In 1970 sold to the Nederlandse Spoorwegen as series NS 2901–2905. In 1975 sold to Ferrocarriles de Vía Estrecha in Spain.

South Korea

• 25 Korean National Railways 4001–4015(From 4011 to 4015, the gear ratio was changed to change the speed to reach 153 km/h (95 mph), and the numbers were revised to 4301 to 4305), 4101–4110

Nigeria

• 25 Nigerian Railways 1101–1125

Norway

• 2 Sydvaranger 1, DE101 – G12 (used on the Kirkenes–Bjørnevatn Line, 1954–97)

Sri Lanka

• 2 Sri Lanka Railways Class M2C 626–627 (Before 2010 it used only for upcountry between Rathmalana, Colombo- Kandy, Badulla.)

Sweden

• 1 locomotive bought by SJ in 1956, named at first T5, later T42. It was built by GM for sales demo in Europe, and SJ bought it afterwards. Now placed at the Swedish Railway Museum.

Venezuela

• Government Coal Mines 01–03

Argentina

• 25 Sarmiento Railway 4501–4525, later 6551–6575.

Australia

• 13 Queensland Rail 1400 class

Brazil

A total of 26 locomotives:

• 6 Rede Mineira de Viação 2708–2712
• 20 Viação Férrea do Rio Grande do Sul 2101–2120

Indonesia

• 11 Indonesian State Railways BB201 01–BB201 11

Mexico

• 6 Ferrocarriles Nacionales de México 5800–5805

New Zealand

• 146 New Zealand DA class locomotive 1400–1545

Sri Lanka

Sri Lanka Railways Class M2D 628

• 12 Sri Lanka Railways.^[7] All except M2 571 still in daily operation (1). Classified as Class M2
  • Class M2 569–573; One locomotive (M2 571) destroyed by terrorism.
  • Class M2A 591–593; 591 damaged by 2004 Indian Ocean Tsunami and later rebuilt
  • Class M2B 594–595
  • Class M2D 628–629

Taiwan

• 52 Taiwan Railway Administration R21–R72; some of their engines were replaced to 12-645E. R56–59: sent to Malawi Railways in July 2006.

United States

• 1 Electro-Motive Division demonstrator 1956

Argentina

A Ferroexpreso Pampeano EMD GR12 on the Sarmiento Railway.

• 60 Sarmiento Railway as model GR12, initially 6576-6635 but later some were renumbered.

Australia

A total of 66 locomotives:

• 10 Queensland Rail 1450 class
• 42 Queensland Rail 1460 class (later on-sold to Tranz Rail and converted to DQ class locomotives for use in New Zealand and Tasmania).
• 14 Western Australian Government Railways A class