The 1948 Summer Olympics were the first to be held after World War II, with the 1944 Summer Olympics having been canceled due to the war. Showing a collective unity after the war, 59 nations competed in 136 different events between 29 July 1948 and 14 August 1948. Germany and Japan were not invited to the games due to security reasons.

The system of apartheid, a racial segregation system practiced in South Africa that discriminated the population on the basis of color, became a debatable topic during the 1964 Summer Olympics held at Tokyo, Japan between October 10 and October 24. This debate ultimately led to the suspension of South Africa from the Games for an indefinite period and was only lifted in 1992.

The Federal Republic of Yugoslavia was banned from participating in 1992 Summer Olympics due to UN sanctions, but individual Yugoslav athletes were allowed to take part as Independent Olympic Participants.

In 2000, the national team of Afghanistan did not fly to Sydney. It was banned due to the extremist rule of the Taliban's oppression of women and its prohibition of sports.

Two Greek athletes were suspended from participating in games in their own country. At the 2004 Olympics in Athens, these athletes were expelled from the national team for deliberately adjusting the accident.