Leisel Marie Jones, OAM (born 30 August 1985) is an Australian former competition swimmer and Olympic gold medallist.
A participant in the 2000 Summer Olympics – at just 15 years old – and 2004 Summer Olympics, she was part of gold-medal-winning Australian team in the women's 4×100-metre medley relay at the Athens Games in 2004 and a gold medalist for 100-meter breaststroke in the 2008 Summer Olympics in Beijing.
In the final of the 100-meter freestyle, Ervin finished fifth with a time of 49.29, ensuring him a spot on the 4×100-meter freestyle relay.
In the final of the 50-meter freestyle, Ervin finished tied for first place with Gary Hall Jr. At the 2000 Summer Olympics, Ervin won one gold and one silver medal.
In 2014, on the Gold Coast, Ervin collected 2 silver medals at the Pan Pacs.
In the 2016 Olympics, Ervin swam the 50 m freestyle, placing 1st in the final with a time of 21.40 seconds.
The competition also marked her international debut in the 200-metre breaststroke, where she came fourth place (.46).
Swimming the third leg, Ervin recorded a split of 47.44, and the team finished with a final time of .44. In his only individual event, the 50-meter freestyle, Ervin entered the final as the second seed with a semi-final time of 21.42, a personal best for him and only 2-hundredths of a second behind the American record.
In the final, Ervin finished in 6th place with a time of 21.65.
Later at the 2003 World Aquatics Championships in Barcelona, Spain, she started setting a world record in the semifinals of the 100-metre breaststroke (.37).
However, she succumbed to nerves in the final and came third, with Luo again winning the event.