The Soviet invasion of Manchuria, formally known as the Manchurian strategic offensive operation (Russian: , romanized: Manchzhurskaya Strategicheskaya Nastupatelnaya Operatsiya) or simply the Manchurian operation ( ), began on 9 August 1945 with the Soviet invasion of the Japanese puppet state of Manchukuo. It was the largest campaign of the 1945 SovietJapanese War, which resumed hostilities between the Union of Soviet Socialist Republics and the Empire of Japan after almost six years of peace. Since 1983, the operation has sometimes been called Operation August Storm after U.S. Army historian David Glantz used this title for a paper on the subject.Soviet gains on the continent were Manchukuo, Mengjiang (the northeast section of present-day Inner Mongolia) and northern Korea. The Soviet entry into the war and the defeat of the Kwantung Army was a significant factor in the Japanese government's decision to surrender unconditionally, as it became apparent that the Soviet Union had no intention of acting as a third party in negotiating an end to hostilities on conditional terms.

The Workers' and Peasants' Red Army, often shortened to the Red Army, was the army and air force of the Russian Soviet Federative Socialist Republic and, after 1922, the Union of Soviet Socialist Republics. The army was established in January 1918. The Bolsheviks raised an army to oppose the military confederations (especially the various groups collectively known as the White Army) of their adversaries during the Russian Civil War. Starting in February 1946, the Red Army, along with the Soviet Navy, embodied the main component of the Soviet Armed Forces; taking the official name of "Soviet Army", until its dissolution in 1991.

The Red Army provided the largest land force in the Allied victory in the European theatre of World War II, and its invasion of Manchuria assisted the unconditional surrender of Imperial Japan. During operations on the Eastern Front, it accounted for 75–80% of casualties the Wehrmacht and Waffen-SS suffered during the war and ultimately captured the Nazi German capital, Berlin.