The Socialist Party of Serbia (Serbian: Socijalistička partija Srbije) is a political party in Serbia. It was founded on July 27, 1990 by Slobodan Milošević, as a merger of Milošević's League of Communists of Serbia (technically the Serbian section of the Communist Party of Yugoslavia), and the League of Socialist Working People of Serbia led by Radmila Andjelkovic .

From 1992 it governed in coalition with other parties - the New Democracy Party from 1992, and including the Serbian Radical Party from 1993. They also contested elections in a coalition with Yugoslav Left , a party led by Milošević's wife. It attempted to join Socialist International, and was nearly unanimously rejected.

After the ousting of Milošević in 2001, the party became one of opposition. In the 2003 Serbian general elections, they won 22 seats in the National Assembly of Serbia.