In what year did a host of countries boycott the Summer Olympics over the Soviet invasion of Afghanistan?

The 1980 Summer Olympics boycott was one part of a number of actions initiated by the United States to protest the Soviet invasion of Afghanistan. The Soviet Union, which hosted the 1980 Summer Olympics, and other countries would later boycott the 1984 Summer Olympics in Los Angeles.

Western governments first considered the idea of boycotting the Moscow Olympics in response to the situation in Afghanistan at the 20 December 1979 meeting of NATO representatives, a fortnight after the invasion of Afghanistan. At that moment, not many of the member governments were interested in the proposal. The idea began to gain popularity in early January when Russian dissident Andrei Sakharov called for a boycott. On 14 January 1980, the Carter Administration joined Sakharov's appeal and set a deadline by which the Soviet Union must pull out of Afghanistan or face the consequences, including an international boycott of the games. On 26 January 1980, Canadian Prime Minister Joe Clark announced that Canada, like the US, would boycott the Olympic Games if Soviet forces did not leave Afghanistan by 20 February 1980.

Sixty-six countries that were invited to participate in the 1980 Olympics did not do so for various reasons including support for the boycott and economic reasons.