Joseph Vissarionovich Stalin (born Iosif Vissarionovich Dzhugashvil) was the Premier of the Soviet Union from 6 May 1941 to 5 March 1953. He was among the Bolshevik revolutionaries who brought about the October Revolution and had held the position of first General Secretary of the Communist Party of the Soviet Union's Central Committee from 1922 until his death in 1953. While formally the office of the General Secretary was elective and was not initially regarded as the top position in the Soviet state, after Vladimir Lenin's death in 1924, Stalin managed to consolidate more and more power in his hands, gradually putting down all opposition groups within the party. This included Leon Trotsky, the Red Army organizer, proponent of world revolution, and principal critic of Stalin among the early Soviet leaders, who was exiled from the Soviet Union in 1929. Instead, Stalin's idea of socialism in one country became the primary line of the Soviet politics.

In power until his death in 1953, Stalin led the USSR during the period of post-war reconstruction, marked by the dominance of Stalinist architecture (most famously represented by the Stalin skyscrapers). The successful development of the Soviet nuclear program enabled the country to become the world's second nuclear weapons power; the Soviet space program was started as spin-off of the nuclear project. In his last years, Stalin also launched the so-called Great Construction Projects of Communism and the Great Plan for the Transformation of Nature.

Following his death, Stalin and his regime have both been questioned on numerous occasions, the most significant of these being the 20th Congress of the Communist Party of the Soviet Union in 1956, when Stalin's successor, Nikita Khrushchev, denounced his legacy and drove the process of de-Stalinization of the Soviet Union. Modern views of Stalin in the Russian Federation remain mixed, with some viewing him as a tyrant while others consider him a capable leader.