The All-Poland Alliance of Trade Unions (OPZZ) is a national trade union center in Poland that was founded on 24 November 1984 after the communist government banned the Solidarity trade union. The OPZZ inherited all of Solidarity's property, and it supported the communist government, having close ties to the Polish United Workers' Party until 1990. Afterwards, it aligned with several post-communist and social democratic parties such as the Democratic Left Alliance. By 2017, the union center had around 500,000 members.