Kathleen Genevieve Ledecky ( lə-DEK-ee; born March 17, 1997) is an American competitive swimmer. She is the most decorated female swimmer in history and the most decorated American woman in Olympic history, with a total of 14 Olympic medals, including nine golds. She is regarded as the greatest female swimmer of all time.
Ledecky has won a record 18 individual gold medals at the World Aquatics Championships, and is the world record holder in the women's 800- and 1500-meter freestyle long course and 1500-meter freestyle short course, as well as the former world record holder in the women's 400-meter freestyle (long course) and 800-meter freestyle (short course). In her international debut at the 2012 London Olympic Games as a 15-year-old, Ledecky unexpectedly won the gold medal in the women's 800-metre freestyle. Four years later, she left Rio de Janeiro as the most decorated female athlete of the 2016 Olympic Games, with four gold medals, one silver medal, and two world records. At the 2020 Olympic Games, Ledecky emerged as the most decorated U.S. female athlete and became the first American female swimmer to win an individual event in three straight Olympiads.