Social Democratic Party of Germany

The Social Democratic Party of Germany (German: Sozialdemokratische Partei Deutschlands [zoˈtsi̯aːldemoˌkʁaːtɪʃə paʁˌtaɪ ˈdɔʏtʃlants], SPD [ɛspeːˈdeː] ) is a social democratic political party in Germany. It is one of the major parties of contemporary Germany. Lars Klingbeil has been the party's leader since the 2021 SPD federal Party convention together with Bärbel Bas, who joined him in June 2025. After losing the 2025 federal election, the party is part of the Merz government as the junior coalition partner. The SPD is a member of 12 of the 16 German state governments and is a leading partner in seven of them.

The SPD was founded in 1875 from a merger of smaller socialist parties, and grew rapidly after the lifting of Germany's repressive Anti-Socialist Laws in 1890 to become the largest socialist party in Western Europe until 1933. In 1891, it adopted its Marxist-influenced Erfurt Program, though in practice it was moderate and focused on building working-class organizations. In the 1912 federal election, the SPD won 34.8 percent of votes and became the largest party in the Reichstag, but was still excluded from government. After the start of the First World War in 1914, the party split between a pro-war mainstream and the anti-war Independent Social Democratic Party, some members of which later formed the Communist Party of Germany (KPD). The SPD played a leading role in the German revolution of 1918–1919 and in the foundation of the Weimar Republic. The SPD politician Friedrich Ebert served as the first president of Germany from 1919 to 1925.