The Reichskommissariat Ukraine (RKU; lit. 'Reich Commissariat of 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.
Reichskommissariat Ukraine was established after the early success of the Wehrmacht's Operation Barbarossa for territory under the military administration of Army Group South Rear Area. The German civil administration was based in Rovno (Rivne) with Erich Koch serving as the only Reichskommissar during its existence.