Karelo-Finnish SSR. The Karelo-Finnish Soviet Socialist Republic (Karelo-Finnish SSR),[a] also called Karelo-Finland, Finno-Karelia and Soviet Karelia or simply known as Karelia, was a republic of the Soviet Union. It existed from 31 March 1940 until it was made part of the Russian SFSR on 16 July 1956 as the Karelian Autonomous Soviet Socialist Republic. The latter became the Republic of Karelia, a federal subject of Russia, on 13 November 1991.