Sarah Kathryn Hammer (born August 18, 1983) is an American former professional racing cyclist and four-times Olympic silver medalist. With eight world championships, she has been called, "America's most decorated track athlete." Hammer announced her retirement from professional Cycling on September 23, 2017.
Hammer is five-times a champion (2006, 2007, 2010, 2011 & 2013) in the individual pursuit and twice a champion (2013 & 2014) in the omnium at the UCI Track Cycling World Championships.
At the 2008 Summer Olympics, Hammer finished fifth overall in the individual pursuit and did not finish in the points race.
At the 2012 Summer Olympics, Hammer won a team silver medal in the Women's team pursuit, as well as an individual silver medal in the women's omnium.
Hammer held the world record in the 3000 m individual pursuit from 2010 until it was broken by Chloé Dygert in 2018.
Hammer announced her retirement from professional Cycling on September 23, 2017.