The Reichskommissariat Ukraine was established by Nazi Germany in 1941 during World War II. It was the civilian occupation regime of much of Nazi German-occupied Ukraine. It was governed by the Reich Ministry for the Occupied Eastern Territories headed by Alfred Rosenberg. Between September 1941 and August 1944, the Reichskommissariat was administered by Erich Koch as the Reichskommissar. The administration's tasks included the pacification of the region and the exploitation, for German benefit, of its resources and people. Adolf Hitler issued a Führer decree defining the administration of the newly-occupied Eastern territories on 17 July 1941.

Erich Koch was a Gauleiter of the Nazi Party (NSDAP) in East Prussia from 1 October 1928 until 1945. Between 1941 and 1945 he was Chief of Civil Administration of Bezirk Bialystok. During this period, he was also the Reichskommissar in Reichskommissariat Ukraine from September 1941 until August 1944 and in Reichskommissariat Ostland from September 1944. After the Second World War, Koch stood trial in Poland and was convicted in 1959 of war crimes and sentenced to death. The sentence was later commuted to life in prison and Koch died of natural causes in his cell at the Barczewo prison on 12 November 1986.