Libby (Lisbeth) Lenton (born January 28, 1985, in Townsville, Queensland) is a member of the Australian Women's Olympic swim team, an Athens gold medalist, and current holder (with teammates Alice Mills, Petria Thomas, and Jodie Henry) of the world record in the women's 4 × 100 metre relay (with a time of 3:35.94). She was also a bronze medalist in the Women's 50 metre Freestyle. She had previously been the holder of the 100m Freestyle world record (53.66s) set at the Olympic swimming Trials held in Sydney, Australia on 31 March 2004, but lost this to teammate Jodie Henry (53.52s) during the semi finals of the event at the Athens Olympics. However, Libby Lenton is still the 2nd fastest ever swimmer in the 100m freestyle, with her old world record.

Libby is coached Swiss-born Stephan Widmer at the Fortitude Valley Pool in Brisbane, and she now trains alongside current 100m breastroke world-record holder Leisel Jones.