Matthew Grevers (born March 26, 1985) is an American competition swimmer who competes in the backstroke and freestyle events, and is a six-time Olympic medalist. He has won a total of thirty-three medals in major international competition, fourteen gold, twelve silver, and seven bronze spanning the Olympics, World Championships, and the Universiade. At the 2008 Summer Olympics, Grevers won gold medals as a member of the U.S. teams in the 4×100-meter freestyle and 4×100-meter medley relays, and a silver medal in the 100-meter backstroke. Four years later at the 2012 Summer Olympics, he won a gold in the 100-meter backstroke and the 4×100-meter medley relay, and a silver in the 4×100-meter freestyle.
At the 2008 Summer Olympics in Beijing, China, Grevers won two gold medals by swimming in the preliminary heats of the 4×100-meter freestyle relay and 4×100-meter medley relay (swimming the backstroke leg) as the Americans went on to win the finals in those events and medals are awarded to participants at any step along the way. Grevers also won an individual silver medal in the 100-meter backstroke in a time of 53.11-second, 0.57 of a second behind the winner, world record holder Aaron Peirsol.