The Spanish Socialist Workers' Party (Spanish: Partido Socialista Obrero Español [paɾˈtiðo soθjaˈlista oˈβɾeɾo espaˈɲol] , PSOE [peˈsoe] or [ˈsoe]) is a social democratic political party in Spain. The PSOE has been in government longer than any other political party in modern democratic Spain: from 1982 to 1996 under Felipe González, 2004 to 2011 under José Luis Rodríguez Zapatero, and since 2018 under Pedro Sánchez.
The PSOE was founded in 1879, making it the oldest party currently active in Spain. The PSOE played a key role during the Second Spanish Republic, being part of the coalition government from 1931 to 1933 and 1936 to 1939, when the republic was defeated in the Spanish Civil War. The party was then banned under the Francoist dictatorship and its members and leaders were persecuted or exiled; the ban was only lifted in 1977 in the transition to democracy. Historically Marxist, it abandoned the ideology in 1979. Like most mainstream Spanish political organizations since the mid–1980s, the PSOE has been considered by experts to have embraced a positive outlook towards European integration.