Robert Lee Nieman (born October 21, 1947) is an American modern pentathlete who competed at the 1976 and 1988 Summer Olympics. Although Nieman had qualified for the 1980 Olympic team he did not compete due to the Olympic Committee's boycott of the 1980 Summer Olympics in Moscow, Russia. He was one of 461 athletes to receive a Congressional Gold Medal instead. Nieman won a team silver medal in épée fencing event at the 1983 Pan American Games.