| Nation |
Party |
| Afghanistan |
Afghan Social Democratic Party |
| Albania |
Social Democratic Party (Albania) |
| Andorra |
Social Democratic Party (Andorra) |
| Austria |
Social Democratic Party of Austria |
| Bosnia-Herzegovina |
Social Democratic Party of Bosnia and Herzegovina |
| Brazil |
Brazilian Social Democracy Party |
| Central African Republic |
Social Democratic Party (Central African Republic) |
| Croatia |
Social Democratic Party of Croatia |
| Czech Republic |
Czech Social Democratic Party |
| Denmark |
Socialdemokratiet |
| East Timor |
Social Democratic Party (East Timor) |
| El Salvador |
Social Democratic Party (El Salvador) |
| Estonia |
Social Democratic Party (Estonia) |
| Ethiopia |
Ethiopian Social Democratic Federal Party |
| Faroe Islands |
Social Democratic Party (Faroe Islands) |
| Finland |
Social Democratic Party of Finland |
| Gabon |
Social Democratic Party (Gabon) |
| Germany |
Social Democratic Party of Germany |
| Gibraltar |
Gibraltar Social-Democrats |
| Guinea-Bissau |
United Social Democratic Party |
| Guyana |
Working People's Alliance |
| Honduras |
Social Democratic Party (Honduras) |
| Iceland |
Social Democratic Party (Iceland) Alliance (Iceland) (Social Democratic Alliance) |
| Japan |
Social Democratic Party (Japan) |
| North Korea |
Korean Social Democratic Party |
| Latvia |
Latvian Social Democratic Workers' Party |
| Lithuania |
Social Democratic Party of Lithuania |
| Malaysia |
Social Democratic Party (Malaysia) (defunct) |
| Mauritius |
Mauritian Social Democrat Party |
| Montenegro |
Social Democratic Party of Montenegro |
| New Zealand |
Social Democratic Party (New Zealand) |
| Nicaragua |
Social Democratic Party (Nicaragua) |
| Nigeria |
Social Democratic Party (Nigeria) |
| Poland |
Social Democratic Party of Poland |
| Portugal |
Partido Social Democrata |
| Romania |
Partidul Social Democrat |
| Russia |
Russian Social Democratic Labour Party with its Bolshevik and Menshevik factions Social Democratic Party of Russia (2001) |
| Rwanda |
Social Democratic Party (Rwanda) |
| Serbia |
Social Democratic Party (Serbia) |
| Sweden |
Swedish Social Democratic Party |
| Switzerland |
Social Democratic Party of Switzerland |
| Tajikistan |
Social Democratic Party (Tajikistan) |
| Tunisia |
Movement of Social Democrats |
| Ukraine |
United Social Democratic Party of Ukraine |
| United Kingdom |
Social Democratic Party (UK) (1981-88) - The original and most prominent incarnation of the SDP Social Democratic Party (UK, 1988) (1988-90) - Continuation by members who had opposed 1988 merger with the Liberal Party Social Democratic Party (UK, 1990) (1990-present) - Continuation of 1988 SDP by members opposed to dissolution Social Democratic Federation - 19th Century political party Social Democratic Party (UK, 1979-82) - Minor party Social Democratic and Labour Party (1970-present) - stands candidates in Northern Ireland but loosely aligned with the Labour Party |
| United States |
Social Democratic Party (United States), 1898 - 1901. Predecessor to the Socialist Party of America
Social Democratic Federation (US) (1935 - 1956)
Social Democratic Party of Pennsylvania
Social Democratic Party of Virginia |
| Uzbekistan |
Adolat Social Democratic Party |
| Zambia |
Social Democratic Party (Zambia) |