The Communist Party of Czechoslovakia was a communist and Marxist–Leninist political party in Czechoslovakia that existed between 1921 and 1992. It was a member of the Comintern. Between 1929 and 1953, it was led by Klement Gottwald. The KSČ was the sole governing party in the Czechoslovak Socialist Republic though it was a leading party along with the Slovak branch and four other legally permitted non-communist parties. After its election victory in 1946, it seized power in the 1948 Czechoslovak coup d'état and established a one-party state allied with the Soviet Union. Nationalization of virtually all private enterprises followed, and a command economy was implemented.

Czechoslovakia was a landlocked state in Central Europe, created in 1918, when it declared its independence from Austria-Hungary. In 1938, after the Munich Agreement, the Sudetenland became part of Nazi Germany, while the country lost further territories to Hungary and Poland. Between 1939 and 1945, the state ceased to exist, as Slovakia proclaimed its independence and Carpathian Ruthenia became part of Hungary, while the German Protectorate of Bohemia and Moravia was proclaimed in the remainder of the Czech Lands. In 1939, after the outbreak of World War II, former Czechoslovak President Edvard Beneš formed a government-in-exile and sought recognition from the Allies.