The Soviet Union officially collapsed on December 25, 1991, when Mikhail Gorbachev resigned as President and announced the end of the Soviet Union as a sovereign state. The Union was formally dissolved the following day, December 26, 1991, with the Soviet parliament voting itself and the Soviet Union out of existence. This marked the end of the USSR and the emergence of 15 independent countries replacing the former superpower.

The collapse was a gradual process that accelerated especially in 1991, following political turmoil such as the failed August coup by communist hardliners and the growing independence declarations by Soviet republics during that year.