How many countries participated in Los Angeles Olympics 1984?

The 1984 Summer Olympics, officially known as the Games of the XXIII Olympiad, was an international multi-sport event that was held from July 28 to August 12, 1984, in Los Angeles (LA), California, United States. This was the second time that LA had hosted the Games, the first being in 1932.

California was the home state of the incumbent U.S. President Ronald Reagan, who officially opened the Games. The logo for the 1984 Games, branded "Stars in Motion", featured red, white and blue stars arranged horizontally and struck through with alternating streaks. The official mascot of the Games was Sam the Olympic Eagle. These were the first Summer Olympic Games under the IOC presidency of Juan Antonio Samaranch.

The 1984 Games were boycotted by a total of fourteen Eastern Bloc countries, including the Soviet Union and East Germany, in direct response to the American-led boycott of the previous 1980 Summer Olympics in Moscow; Romania was the only Eastern Bloc nation that opted to attend the Games. Iran and Libya also chose to boycott the Games for separate reasons. Despite the field being depleted in certain sports due to the mass boycott, 140 National Olympic Committees took part, which was a record at the time.