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.

Oscar Leonard Carl Pistorius is a South African former professional sprinter and convicted murderer. Both of his feet were amputated when he was 11 months old as a result of a congenital defect; he was born missing the outside of both feet and both fibulae. Pistorius ran in both nondisabled sprint events and in sprint events for below-knee amputees. He was the 10th athlete to compete at both the Paralympic Games and Olympic Games.