The USSR effectively collapsed at the end of 1991, with two key dates often cited:

  • December 25, 1991 – Mikhail Gorbachev resigned as president of the Soviet Union and transferred powers to Boris Yeltsin, marking the political end of the union’s leadership.
  • December 26, 1991 – The Soviet of the Republics (the upper chamber of the Supreme Soviet) formally voted the Soviet Union out of existence, which is the legal date of the USSR’s dissolution.

So when people ask “when did the USSR collapse,” the most precise answer is December 26, 1991 , though many also highlight December 25, 1991 as the symbolic moment when it ceased to function as a state.