The 20th Congress of the Communist Party of the Soviet Union was held during February 14—February 26 1956. It is known especially for Nikita Khrushchev's Secret Speech, which denounced recently deceased Soviet dictator Joseph Stalin.

During the morning closed session of the last day of the Congress, Khrushchev, the Communist Party Secretary, took the opportunity to give a stinging rebuke of the policies of Stalin, his late predecessor. Khrushchev denounced Stalin's cult of personality, and Stalin's apparent support of the concept of individuality. He went on to denounce a list of crimes committed by Stalin's supporters, many of which had previously been denied by the Soviet Union.

The speech shocked delegates to the congress, as it flew in the face of years of Soviet propaganda, which had claimed that Stalin was a wise, peaceful, and fair leader. After long deliberations, in a month the speech was reported to general public, but the full text was published only in 1989.

One of its most notable fallouts was the collapse of the United States Communist Party which had previously been composed of many die-hard Stalinists. Stalin's fall from grace left the party badly fractioned, and it never regained its former influence.

See also: Congress of the CPSU