South Africa competed at the 2012 Summer Olympics in London, United Kingdom, from 27 July to 12 August 2012. This was the nation's eighteenth participation overall and sixth consecutive appearance at the Summer Olympics in the post-apartheid era. The South African Sports Confederation and Olympic Committee (SASCOC) sent a total of 125 athletes to the Games, 67 men and 58 women, to compete in 17 sports. Field hockey and women's football were the only team-based sports in which South Africa were representation at these Olympic Games. There was only a single competitor in archery, BMX cycling, judo, shooting and weightlifting.

Italy competed at the 2012 Summer Olympics in London, from 27 July to 12 August 2012. This nation has competed at every Summer Olympic Games in the modern era, except for the 1904 Summer Olympics in St. Louis. The Italian National Olympic Committee sent the nation's smallest delegation to the Games since the 1988 Summer Olympics in Seoul. A total of 285 athletes, 162 men and 123 women, competed in 22 sports.