The Polish Socialist Party (Polska Partia Socjalistyczna, PPS) was one of the most important Polish political parties from its inception in 1892 until 1948, when it merged with the communist Polish Workers' Party (PPR) to form the Polish United Workers' Party (PZPR), the ruling party in the People's Republic of Poland.

A new party of the same name, which intends to carry on the tradition of the original PPS, was established by left-wing oppositionals such as Jan Jozef Lipski in 1987. However, the new PPS remained a marginal group within the political landscape of the Third Republic.

Political parties in Poland | History of Poland

Lenkijos socialistų partija | Polska Partia Socjalistyczna