1951 Polish–Soviet territorial exchange

The 1951 Polish-Soviet territorial exchange, also known as the Polish-Soviet border adjustment treaty of 1951, was a border agreement signed in Moscow between the Republic of Poland and the Soviet Union. It involved approximately 480 km² (185 sq mi) of land along their shared border. The treaty was signed on 15 February 1951, ratified by Poland on 28 May 1951, and by the Soviet Union on 31 May. It modified the border treaty of 16 August 1945, and came into effect on 5 June 1951. Since Poland was a satellite state within the Soviet sphere of influence, the exchange favored the Soviet Union economically due to the valuable coal deposits relinquished by Poland. Following the agreement, the Soviets constructed four large coal mines within eight years, with a combined annual mining capacity of 15 million tons.

In return, the Soviet Union transferred part of the Drohobych Oblast (1939-1959) of the Ukrainian Soviet Socialist Republic. The areas ceded included the city of Ustrzyki Dolne and the villages of Czarna (Ukrainian: Чорна Chorna), Shevchenko (which later regained its prewar Polish name of Lutowiska in 1957), Krościenko, Bandrów Narodowy, Bystre, and Liskowate. This territory was incorporated into the Krosno Voivodeship in 1975 and subsequently became part of the Subcarpathian Voivodeship on 1 January 1999. The Ukrainian SSR, as a constituent Soviet republic, did not have a say in this process.

As part of the exchange, Poland relinquished a portion of the Lublin Voivodeship, which included the cities of Bełz (Ukrainian: Белз, Belz), Uhnów (Угнів, Uhniv), Krystynopol (Кристинопіль, Krystynopil), and Waręż (Варяж, Variazh). This territory now forms part of the Sheptytskyi Raion in the Lviv Oblast of Ukraine.