Yane Márcia Campos da Fonseca Marques is a modern pentathlon athlete from Brazil. She became nationally known despite the obscurity of her sport in the country after winning a bronze medal at the 2012 Summer Olympics, the first Latin American to medal and the only woman to do so.

Brazil competed at the 2012 Summer Olympics in London, from 27 July to 12 August 2012. This was the nation's twenty-first appearance at the Summer Olympics, having missed the 1928 Summer Olympics in Amsterdam. The Brazilian Olympic Committee sent a total of 258 athletes to the Games, 136 men and 122 women, to compete in 24 sports. Brazil left London with a total of 17 Olympic medals, winning their third largest number of medals at a single games.