The Treaty of Tartu (, ) between Finland and Soviet Russia was signed on 14 October 1920 after negotiations that lasted for four months. The treaty confirmed the border between Finland and Soviet Russia after the Finnish civil war and Finnish volunteer expeditions in Russian East Karelia. Ratifications of the treaty were exchanged in Moscow on December 31, 1920. The treaty was registered in the League of Nations Treaty Series on March 5, 1921.