The Ukrainian War of Independence was a series of conflicts involving many adversaries that lasted from 1917 to 1921 and resulted in the establishment and development of a Ukrainian republic, most of which was later absorbed into the Soviet Union as the Ukrainian Soviet Socialist Republic of 1922–1991.

The war consisted of military conflicts between different governmental, political and military forces. Belligerents included Ukrainian nationalists, Ukrainian anarchists, Bolsheviks, the forces of Germany and Austria-Hungary, the White Russian Volunteer Army, and Second Polish Republic forces. They struggled for control of Ukraine after the February Revolution (March 1917) in the Russian Empire. The Allied forces of Romania and France also became involved. The struggle lasted from February 1917 to November 1921 and resulted in the division of Ukraine between the Bolshevik Ukrainian SSR, Poland, Romania, and Czechoslovakia.

The conflict is frequently viewed within the framework of the Southern Front of the Russian Civil War of 1917–1922, as well as the closing stage of the Eastern Front of the First World War of 1914–1918.