Marcus Laborne Mattioli (born 18 October 1960 in Belo Horizonte) is a former international freestyle and butterfly swimmer from Brazil, who participated in the 1980 Summer Olympics for his native country. There he won the bronze medal in the men's 4×200-metre freestyle relay event at the 1980 Summer Olympics, alongside Jorge Fernandes, Cyro Delgado, and Djan Madruga. Participated at the 1978 World Aquatics Championships in West Berlin, where he finished 34th in the 100-metre freestyle, and 29th in the 200-metre freestyle. Mattioli still swim, now breaking world records in the Masters category.