The activity of the Ukrainian Greek-Catholic Church (UGCC; until the 1960s – the Greek Catholic Church) on the territory of modern Poland in the time frame from the forced resettlement of Ukrainian Greek-Catholics as part of the "Visula" action in 1947 to the next wave of mass migration of Ukrainians to Poland related to the Russian-Ukrainian war in 2022 is considered. The peculiarities of the establishment of new parishes in the northern and western regions of Poland, coexistence with Roman Catholic and Orthodox communities in the conditions of unrecognized semi-legal work of the Church are traced. The differences in perception and obstacles of the Roman Catholic Church (RCC) and the secular communist authorities regarding the activity of Greek Catholic priests, who, in the conditions of deprivation of governance and structure of the Church, found themselves between the choice of Latinization, dual rites or underground work and attempts to legalize the activities of their parishes, have been established. Highlighted: the role of the Vatican in firstly promoting the preservation of the Church within the framework of the RCC, and later, in the wake of political liberalization, the possibilities of restoring and preserving the structure of the UGCC in Poland; activity in the legal protection of the rights of the Church of priests Vasyl Hrynyk, Myroslav Ripetskyi, Ivan Yaremin, and others.

The restoration and changes in the structure of the Church at the end of the 20th - beginning of the 21st century are analyzed. with the establishment of the Przemyśl-Warsaw Metropolitanate and Archdiocese, Wrocław-Koszały and Olsztyn-Gdansk Diocese; creation of new parishes for labor migrants from Ukraine in places of their compact settlement in cities and industrial centers. The charitable, cultural and educational activities of the UGCC for the Ukrainian diaspora, as well as new challenges caused by a new wave of migration associated with the Russian-Ukrainian war, were considered.