The Social Democratic Party of Croatia (SDP) is a social democratic party in Croatia that was founded on 3 November 1990 as a successor to the League of Communists of Croatia. The party abandoned Titoism in favor of social democracy and anti-fascism, and it was opposed to the conservative Croatian Democratic Union during the 1990s and the early 21st century. The party supported Croatia's membership in the European Union, and it became the second-largest party in the country.