Solidarity, a Polish trade union, was founded as the first independent labor union in an Eastern Bloc country.

Solidarity, full name Independent Self-Governing Trade Union "Solidarity", is a Polish trade union founded in August 1980 at the Lenin Shipyard in Gdańsk, Poland. Subsequently, it was the first independent trade union in a Warsaw Pact country to be recognised by the state.

A trade union or labor union, often simply referred to as a union, is an organization of workers whose purpose is to maintain or improve the conditions of their employment, such as attaining better wages and benefits, improving working conditions, improving safety standards, establishing complaint procedures, developing rules governing status of employees and protecting and increasing the bargaining power of workers.

Solidarity, a Polish non-governmental trade union, was founded on August 14, 1980, at the Lenin Shipyards by Lech Wałęsa and others. In the early 1980s, it became the first independent labor union in an Eastern Bloc country. Solidarity gave rise to a broad, non-violent, anti-Communist social movement that, at its height, claimed some 9.4 million members. It is considered to have contributed greatly to the Revolutions of 1989.

The Eastern Bloc, also known as the Communist Bloc (Combloc), the Socialist Bloc, the Workers Bloc, and the Soviet Bloc, was an unofficial coalition of communist states of Central and Eastern Europe, Asia, Africa, and Latin America that were aligned with the Soviet Union and existed during the Cold War (1947–1991). These states followed the ideology of Marxism–Leninism, in opposition to the capitalist Western Bloc. The Eastern Bloc was often called the "Second World", whereas the term "First World" referred to the Western Bloc and "Third World" referred to the non-aligned countries that were mainly in Africa, Asia, and Latin America but notably also included former pre-1948 Soviet ally Yugoslavia, which was located in Europe.