Argentina competed at the 2012 Summer Olympics in London, United Kingdom, from 27 July to 12 August 2012. This was the nation's twenty-third appearance at the Summer Olympic Games, having missed only three editions: the sparsely attended 1904 Summer Olympics in St. Louis, the 1912 Summer Olympics in Stockholm, and the 1980 Summer Olympics in Moscow, because of the United States boycott.

Comité Olímpico Argentino sent a total of 137 athletes to the Games, 96 men and 41 women, to compete in 22 sports. Archery, badminton, diving, football, modern pentathlon, water polo, weightlifting, rhythmic gymnastics and trampoline were the only sports in which Argentina had no representation in these Olympic Games. Among the sports, Argentina made its Olympic debut in synchronized swimming and men's handball. Luciana Aymar, captain of Argentina women's national field hockey team, who competed at her fourth Olympics, was the nation's flag bearer at the opening ceremony.