Leisel Marie Jones, OAM (born 30 August 1985) is an Australian former competition swimmer and Olympic gold medallist.

While at Southern Cross Catholic College, Jones used to train at the Redcliffe club in Scarborough, Queensland, and was coached by Ken Wood.

[4] After her disappointing campaign in Athens, Jones moved to train at the Fortitude Valley Pool in Brisbane, Australia, alongside Libby Lenton, under Swiss-born coach Stephan Widmar at the Commercial Swimming Club.

[5][6] Following the move, Jones began to speak openly about the depression and self-esteem issues that had plagued her following her being thrust into the spotlight at such a young age.

Some, including Dawn Fraser, believed Jones had acted immaturely and ungratefully, particularly in her indifferent displays of emotion during post-race interviews and medal ceremonies.

Jones swam a personal best in the final at the Sydney Olympics to claim an unexpected silver medal behind American Megan Quann.

[12] She also combined with Dyana Calub, Petria Thomas and Susie O'Neill in the 4×100-metre medley relay to win silver, again behind the Americans.

She also collected a gold in the medley relay alongside Calub, Thomas and Sarah Ryan, the first time that the US women had been beaten at world or Olympic level in this event, excluding the systemically doped East German and Chinese teams.

In the month leading up to the Athens Olympics, Jones set a world record (2:22.96) in the 200-metre breaststroke in a meet in Brisbane, Australia.

In the 200-metre breaststroke, she attempted to take an attacking approach, but faded in the last 50 metres and was pipped to the wall by Amanda Beard, winning silver.

[16] She later won another gold in the 200-metre breaststroke and completed the sweep with the gold medal in the 100-metre in a world record time of 1:05.09 – an effort that saw her own world record reduced 0.62 of a second and was declared "Beamonesque" by aquatics journalist Craig Lord, a reference to Bob Beamon's legendary long jump at the Mexico City Olympics.

A fourth gold medal in world record time in the 4×100-metre medley relay with Sophie Edington, Jessicah Schipper and Libby Lenton rounded off her Commonwealth Games.

She then left Brisbane and Widmer to move to Melbourne to train under Rohan Taylor, so that she could live with her fiancé Marty Pask, an Australian rules footballer with the Western Bulldogs.

Her dissolution of a successful partnership raised eyebrows and many questioned whether putting her personal life ahead of a proven competitive formula would backfire in the pool.

Jones won gold at the 2008 Beijing Olympics in 100-metre breaststroke, touching the line a full body length ahead of her rival.

[19] Together with Emily Seebohm, Alicia Coutts and Melanie Schlanger, she won a silver medal for Australia in the 4×100-metre medley relay.