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.

[2][3] 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.

[4] 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.