Emma Jennifer McKeon, AM (born 24 May 1994) is a retired Australian competitive swimmer. She is an eight-time world record holder, three current and five former, in relays. Her total career haul of 14 Olympic medals following the 2024 Olympic Games made her the most decorated Australian, the third-most decorated swimmer, and the seventh-most decorated athlete in Olympic history and included one gold medal from the 2016 Summer Olympics in Rio de Janeiro, four gold medals from the 2020 Summer Olympics in Tokyo and one gold medal from the 2024 Summer Olympics in Paris. With four gold and three bronze medals she was the most decorated athlete across all sports at the 2020 Summer Olympics, and tied for the most medals won by a woman in a single Olympic Games. She also won 20 medals, including five gold medals, at the World Aquatics Championships; and a record 20 medals, including 14 gold, at the Commonwealth Games.
In 2024, McKeon surpassed Ian Thorpe for the most number of Olympic gold medals won over the course of an Australian athlete's career with six total gold medals earned at her three appearances at the Olympic Games. She was also the highest scoring competitor, male or female, for the 2021 FINA Swimming World Cup where she earned a total of fourteen medals, including ten gold medals and four silver medals.