Madisyn Cox (born May 30, 1995) is an American former swimmer specializing in individual medley events.

[7] Cox qualified to swim the 200-meter individual medley at the World Championships after finishing second at the 2017 US Nationals.

Cox was banned from competition for six months after a urine sample taken in February 2018 tested positive for trimetazidine.

[8] Upon analysis of both opened and sealed bottles of Cooper Complete Elite Athletic multivitamins, the Court of Arbitration for Sport determined that the multivitamins were the source, and reduced Cox's suspension to six months.

Cox previously announced that she would be retiring from the sport following the 2021 season, in order to begin medical school at the McGovern Medical School, part of the University of Texas Health Science Center at Houston.