Hayley Peirsol (born 9 August, 1985 in Irvine, California) is American long-distance swimmer who swam for Auburn University in Alabama. She previously swam under Brent Lorenzen with Irvine Novaquatics. She is currently training with Club Wolverine at the University of Michigan under Bob Bowman in preparation for the 2008 Olympics in Beijing.

Her brother, American backstroker, Aaron Peirsol is an Olympic gold medalist and world record holder. She is majoring in Criminology and enjoys cooking.