There are a large number of political parties named the Social Democratic Party:
- Albania - Social Democratic Party
- Andorra - Social Democratic Party
- Austria - Social Democratic Party of Austria
- Brazil - Social Democratic Party of Brazil
- Croatia - Social Democratic Party of Croatia
- Czech Republic - Czech Social Democratic Party
- Denmark, Social Democracy
- East Timor - Social Democratic Party
- Finland - Finnish Social Democratic Party
- Germany - Social Democratic Party of Germany
- Japan - Social Democratic Party
- Latvia - Social Democratic Party
- Portugal - Social Democratic Party
- Romania - Social Democratic Party
- Rwanda - Social Democratic Party
- Serbia and Montenegro - Social Democratic Party
- Slovenia - Social Decmocratic Party of Slovenia
- Sweden - Social Democratic Workers' Party
- Switzerland - Social Democratic Party of Switzerland
- Tunisia - Movement of Social Democrats
- United Kingdom - Social Democratic Party (UK), Social Democratic Federation
- The Russian Social Democratic Labour Party was a historical Russian party that later became the Communist Party of the Soviet Union.