The Workers' and Peasants' Red Army (Russian: Рабо́че-крестья́нская Кра́сная а́рмия, Rabóče-krestʹjánskaja Krásnaja ármija), often shortened to the Red Army, was the army and air force of the Bolshevik Party, 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 German capital, Berlin.

Up to 34 million soldiers served in the Red Army during World War II, 8 million of which were non-Slavic minorities. Officially, the Red Army lost 6,329,600 killed in action (KIA), 555,400 deaths by disease and 4,559,000 missing in action (MIA) (most captured). The majority of the losses, excluding POWs, were ethnic Russians (5,756,000), followed by ethnic Ukrainians (1,377,400). Of the 4.5 million missing, 939,700 rejoined the ranks in liberated Soviet territory, and a further 1,836,000 returned from German captivity. The official grand total of losses amounted to 8,668,400. This is the official total dead, but other estimates give the number of total dead up to almost 11 million. Officials at the Russian Central Defense Ministry Archive (CDMA) maintain that their database lists the names of roughly 14 million dead and missing service personnel.