Janet Beth Evans (born August 28, 1971) is an American former competition swimmer who swam from 1989 to 1992 for Stanford University and specialized in distance freestyle events. Evans was a world champion and world record-holder, and won a total of four gold medals in the 400 and 800-meter freestyle events at the 1988 and the 1992 Olympics. In the late 1980s Evans was the first woman to hold three world records simultaneously in the 400, 800, and 1500-meter freestyle and was the first American woman to win four individual Olympic gold medals in swimming

Janet Evans was a natural born swimmer who was swimming laps in the pool at the age of two. In 1987, aged just 15, Evans broke the world records in the 400m, 800m and 1500m freestyle events. Her achievements were all the more remarkable given her small stature, slight build and unorthodox windmill stroke.

At the 1988 Seoul Games, Evans dominated every event she entered, winning the 400m individual medley, the 400m freestyle and the 800m freestyle. She broke her own world record in the 400m freestyle and finished almost three meters ahead of her nearest rival in the 800m freestyle.

Evans entered the 1992 Barcelona Games on a six-year winning streak at 400m. However, she was caught in the last laps and beaten into second place by just 30 centimeters. Two days later, Evans made amends in the 800m, leading from start to finish and winning by eight meters to defend her title.

Between 1986 and 1995, Janet Evans won 25 out of 27 major international races at 400m and 22 out of 23 at 800m. Her world record for the 800m freestyle lasted through four Olympic Games until it was finally broken at the 2008 Beijing Games.

In 2010, Evans returned to competitive swimming as a United States Masters swimmer.

On November 3, 2016, Evans was chosen to serve as co-Grand Marshal of the 2017 Rose Parade.

Evans served as Vice Chair and Athletes director for the Los Angeles 2024 Olympic bid committee and traveled with the team to promote Los Angeles as a candidate city. Los Angeles was ultimately awarded the 2028 Summer Olympics at the 131st IOC Session in Lima, on September 13, 2017. As of 2020, Evans works with the organizing committee for the 2028 Summer Olympics in the executive leadership role of Chief Athlete Officer.