Reichkommissariat Ukraine was an administrative unit that encompassed most of Ukrainian territory under civilian rule during the German occupation 1941-44. Reichkommissariat Ukraine was established in September 1941 and was made up of Volyn, Polisia, Right Bank Ukraine and part of the Poltava oblast; in September 1942 Dnipropetrovsk, Zaporizhia, and Kherson oblasts were annexed to the Reichkommissariat Ukraine – the rest of Left Bank Ukraine remained under military rule. Galicia became part of the Generalgouvernment, while northern Bukovyna and Transdniestria became part of Romania. Reichkommissariat Ukraine had about 17 million civilian inhabitants.

Erich Koch, who embodied the ruthlessness of Nazi occupation policy, ruled Reichkommissariat Ukraine. Occupation policies in Reichkommissariat Ukraine were more brutal than in the Generalgouvernment. The death penalty was introduced for even minor offenses. Education was reduced to four grades of primary school, and higher education restricted only to specialized vocational courses. Cultural and media institutions were closed. Medical services and food supplies were reduced, and the population was mobilized to work for the Four Year Plan. Many were taken to work in Germany as ostarbeiters.

Reichkommissariat Ukraine was an important part of the German lebensraum plans; after the war, the territory was to be annexed to the Reich and Ukrainians were to be resettled east of the Ural mountains to make room for German colonists. The black earth of Ukraine was to be used to feed the new German empire. These plans were interrupted by the Soviet victory at Stalingrad and the gradual reoccupation of Ukraine by the Red Army; Reichkommissariat Ukraine was formally liquidated in November 1944.