The Soviet occupation of Latvia in 1940  refers, according to the European Court of Human Rights, the Government of Latvia, the United States Department of State, and the European Union, to the military occupation of the Republic of Latvia by the Soviet Union ostensibly under the provisions of the 1939 Nazi - Communist (Molotov–Ribbentrop also Stalin- Hitler) Pact with Nazi Germany.

When World War II started in September 1939 with the joint German and USSR invasion of Poland, Latvia (also Lithuania, Estonia, etc.) had already come under the Soviet sphere of influence in the Nazi–Communist Pact and its Secret Additional Protocol of 23rd August 1939