Massacres of Poles in Volhynia and Eastern Galicia by the Ukrainian Insurgent Army within the Reichskommissariat Ukraine (Volhynia) peak.

The Massacres of Poles in Volhynia and Eastern Galicia were carried out in German-occupied Poland by the Ukrainian Insurgent Army (UPA), with the support of parts of the local Ukrainian population, against the Polish minority in Volhynia, Eastern Galicia, parts of Polesia, and the Lublin region from 1943 to 1945. The UPA's actions resulted in up to 100,000 Polish deaths.

The Ukrainian Insurgent Army was a Ukrainian nationalist partisan formation founded by the Organisation of Ukrainian Nationalists (OUN) on 14 October 1942. The UPA launched guerrilla warfare against Nazi Germany, the Soviet Union, and both the Polish Underground State and Polish Communists. The UPA carried out massacres of Poles in Volhynia and Eastern Galicia, which are recognized by Poland as a genocide.

The Reichskommissariat Ukraine was an administrative entity of the Reich Ministry for the Occupied Eastern Territories of Nazi Germany from 1941 to 1944. It served as the German civilian occupation regime in the Ukrainian SSR, and parts of the Byelorussian SSR, Russian SFSR, and eastern Poland during the Eastern Front of World War II.

Volhynia or Volynia is a historic region in Central and Eastern Europe, between southeastern Poland, southwestern Belarus, and northwestern Ukraine. The borders of the region are not clearly defined, but in Ukraine it is roughly equivalent to Volyn Oblast, Rivne Oblast, and the northern part of the Ternopil Oblast. The territory that still carries the name is Volyn Oblast.