The Soviet Union announces a boycott upon the Summer Olympics at Los Angeles, later joined by 14 other countries.

The Union of Soviet Socialist Republics (USSR), commonly known as the Soviet Union, was a transcontinental country that spanned much of Eurasia from 1922 until it dissolved in 1991. During its existence, it was the largest country by area, extending across eleven time zones and sharing borders with twelve countries, and the third-most populous country. An overall successor to the Russian Empire, it was nominally organized as a federal union of national republics, the largest and most populous of which was the Russian SFSR. In practice, its government and economy were highly centralized. As a one-party state governed by the Communist Party of the Soviet Union (CPSU), it was the flagship communist state. Its capital and largest city was Moscow.

The boycott of the 1984 Summer Olympics in Los Angeles followed four years after the American-led boycott of the 1980 Summer Olympics in Moscow. The boycott involved nineteen countries: fifteen from the Eastern Bloc led by the Soviet Union, which initiated the boycott on May 8, 1984; and four from the Non-Aligned Movement, which boycotted on their own initiatives. The boycotting countries organized alternative sporting events which functioned as a replacement for the Olympics in everything but name, called the Friendship Games, which were held in various Eastern Bloc countries from July to September of 1984. Although the boycott affected Olympic events that were normally dominated by the absent countries, 140 nations still took part in the Los Angeles Games, which was a record at the time.

The 1984 Summer Olympics were an international multi-sport event held from July 28 to August 12, 1984, in Los Angeles, California, United States. It marked the second time that Los Angeles had hosted the Games, the first being in 1932. This was the first of two consecutive Olympic Games to be held in North America, with Calgary, Alberta, Canada, hosting the 1988 Winter Olympics. California was the home state of the incumbent U.S. president Ronald Reagan, who officially opened the Games. These were the first Summer Olympic Games under the IOC presidency of Juan Antonio Samaranch.