Nathaniel James Dusing (born November 25, 1978) is an American former competition swimmer, Olympic medalist, and former world champion.
Dusing represented the United States at two consecutive Summer Olympics. At the 2000 Summer Olympics in Sydney, Australia, he earned a silver medal by swimming for the second-place U.S. team in the preliminary heats of the men's 4×200-meter freestyle relay. Four years later, at the 2004 Summer Olympics in Athens, Greece, he received a bronze medal by swimming for the third-place U.S. team in the preliminary heats of the men's 4×100-meter freestyle relay.
He was also a member of gold medal-winning U.S. relay teams in the 4×100-meter freestyle at the 2005 World Aquatics Championships, and the 2004 World Short Course Championships.