Aaron Wells Peirsol is an American former competition swimmer and backstroke specialist who is a former world champion and world record-holder. He is a three-time Olympian and seven-time Olympic medalist. As a member of the U.S. national team, he holds the world record in the men's 4×100-meter medley relay. Individually, he currently holds the world record in the 200-meter backstroke event. In February 2011, Peirsol announced his retirement, saying, "I ended up doing everything I set out to do."
Peirsol's successes have earned him the American Swimmer of the Year Award once.