Former
- Afghanistan – People's Democratic Party of Afghanistan
- Albania – Albanian Party of Labor
- Algeria – Socialist Vanguard Party
- Antigua and Barbuda – Antigua Caribbean Liberation Movement
- Australia – Communist Party of Australia
- The Bahamas – Vanguard Nationalist and Socialist Party
- Belgium – Belgian Socialist Party, Communist Party of Belgium
- Benin – People's Revolutionary Party of Benin
- Bolivia – Party of the Revolutionary Left
- Brazil – Brazilian Communist Party (original)
- Bulgaria – Bulgarian Communist Party
- Burkina Faso – Patriotic League for Development
- Burma – Burma Socialist Party, Communist Party of Burma (original)
- Burundi – Burundi Workers' Party
- Cambodia – Kampuchean People's Revolutionary Party, Khmer Rouge
- Cameroon – Union of the Peoples of Cameroon (original)
- Canada – Co-operative Commonwealth Federation, Cape Breton Labour Party
- Colombia – Patriotic Union
- Czechoslovakia – Communist Party of Czechoslovakia
- Dominican Republic – Dominican Communist Party
- Egypt – Arab Socialist Union
- Ethiopia – All-Ethiopia Socialist Movement, Ethiopian People's Revolutionary Party, Workers' Party of Ethiopia
- Finland – Communist Party of Finland, Finnish People's Democratic League
- France – French Section of the Workers' International, Unified Socialist Party, Revolutionary Communist League, Workers' Party
- Germany – Communist Party of Germany, Independent Social Democratic Party of Germany, Labour and Social Justice – The Electoral Alternative, Party of Democratic Socialism, Socialist Unity Party of Germany, Socialist Unity Party of West Berlin, Socialist Workers' Party of Germany, Spartacus League
- Grenada – New Jewel Movement
- Guatemala – Guatemalan Party of Labor
- Guinea – Democratic Party of Guinea (original)
- Hungary – Hungarian Communist Party, Hungarian Workers' Party, Hungarian Socialist Workers' Party
- Iceland – Social Democratic Party, People's Alliance, Communist Party of Iceland
- Indonesia – Communist Party of Indonesia, Socialist Party of Indonesia
- Israel – Mapai, Mapam, Matzpen
- Italy – Italian Communist Party, Italian Socialist Party, Democrats of the Left
- Japan – Japan Socialist Party
- Kenya – Kenya People's Union
- Malaysia – Communist Party of Malaya
- Netherlands – Communist Party of the Netherlands, Democratic Socialists '70, Pacifist Socialist Party, Political Party of Radicals, Social Democratic Workers' Party
- New Zealand – Communist Party of New Zealand
- Niger – Sawaba
- Norway – Red Electoral Alliance, Workers' Communist Party
- Pakistan – National Awami Party
- Poland – Social Democracy of the Kingdom of Poland and Lithuania, Communist Party of Poland, Polish Workers' Party, Polish United Workers' Party
- Puerto Rico – Puerto Rican Socialist Party, Puerto Rican Communist Party
- Romania – Romanian Communist Party
- Russia – Russian Social Democratic Labor Party, Socialist-Revolutionary Party, Mensheviks
- San Marino – Sammarinese Communist Party, Sammarinese Socialist Party
- Somalia – Somali Revolutionary Socialist Party
- Soviet Union – Communist Party of the Soviet Union
- Spain – Workers' Party of Marxist Unification
- Sudan – Sudanese Socialist Union
- Ukraine – Borotbisty
- United Kingdom – Communist Party of Great Britain, Independent Labour Party, Social Democratic Federation
- United States – American Labor Party, Farmer-Labor Party, New Alliance Party, Nonpartisan League, Proletarian Party of America, Social Democratic Party, Socialist Party of America, Workers Party, Workingmen's Party of the United States
- Yugoslavia – League of Communists of Yugoslavia
Read more about this topic: Left-wing Political Parties