Evelyn Kawamoto grew up swimming in Hawai’i and qualified for the US Olympic Trials in 1948 at age 14, although she failed to make the team that year. In 1949 Kawamoto broke American records in the 300m IM and the 200m breaststroke on the same day. She won both events at the 1949 US Long-course Nationals. In 1950 she defended the 200 breaststroke crown when she finished in a dead-heat with Marge Hulton, with both breaking the American record.
In June 1952, Kawamoto of the Hawaiian SC bettered her own U.S. 400m freestyle record and the following month she won this event at the Final Trials by a margin of more than five seconds. At the Olympics she took third place behind two Hungarians and won a second bronze medal in the relay. Kawamoto married her fellow Olympian from Hawaii, Ford Konno, who won four medals at the 1952 Games.