Kathleen Baker (born February 28, 1997) is an American competition swimmer who specializes in freestyle and backstroke events. At the 2016 Summer Olympics, she won a gold medal in the 4x100-meter medley relay and a silver medal in the individual 100-meter backstroke. She is the former world-record holder in 100 meter backstroke, set on July 28, 2018 in 58.00 at the William Woollett Jr. Aquatics Center in Irvine, CA. Baker is also the former world-record holder in the 4x100 meter medley relay with Lilly King, Dana Vollmer, and Simone Manuel.