Gretchen Walsh is a competitive American swimmer. She holds two world junior records in mixed gender relay events as well as American records in the 50 yard freestyle, 100 yard freestyle, 100 yard butterfly, 100 yard backstroke, 4×50 yard freestyle relay, 4×50 yard medley relay, 4×100 yard freestyle relay, and 4×100 yard medley relay. In 2022, she became the fastest female freshman to swim the 50 yard freestyle in the NCAA, with a time of 20.95 seconds, and earned the NCAA title in the 100 yard freestyle, with a time of 46.05 seconds, and the national title in the 100 meter butterfly. In 2023, she won the women's NCAA Division I title in the 100 yard backstroke, with an American record time of 48.26 seconds, and the 100 yard freestyle, with a 45.61. She won six gold medals at the 2019 World Junior Championships as well as five gold medals and one silver medal at the 2018 Junior Pan Pacific Swimming Championships. She competes collegiately for the University of Virginia.