Margaret Hoelzer (born March 30, 1983 in Huntsville, Alabama) is an American swimmer. On July, 1 2008, she qualified to swim in the 100m backstroke at the 2008 Olympics. On July 5, 2008, Hoelzer broke Kirsty Coventry's world record of 2:06.39 in the 200m backstroke with a time of 2:06.09, ultimately qualifying for her second event in the 2008 Olympics.