The 1980 Summer Olympics, officially known as the Games of the XXII Olympiad and commonly known as Moscow 1980, were an international multi-sport event held from 19 July to 3 August 1980 in Moscow, Soviet Union, in present-day Russia. The Games were the first to be staged in Eastern Europe, and remain the only Summer Olympics held there, as well as the first Olympic Games and only Summer Olympics to be held in a Slavic language-speaking country. They were also the only Summer Olympic Games to be held in a communist country until the 2008 Summer Olympics held in China. These were the final Olympic Games under the IOC Presidency of Michael Morris, 3rd Baron Killanin.
Eighty nations were represented at the Moscow Games, the smallest number since 1956. Led by the United States, 66 countries boycotted the games entirely, because of the Soviet–Afghan War. Several alternative events were held outside of the Soviet Union. Some athletes from some of the boycotting countries participated in the games under the Olympic Flag. The Soviet Union later boycotted the 1984 Summer Olympics in Los Angeles.