Lisa Jane Weightman (born 16 January 1979) is an Australian long distance runner and four time Olympian who specializes in the marathon event. At the 2020 Tokyo Olympics she came 26th in the Women's marathon with a time of 2:34.19, 7 minutes behind the eventual winner, Peres Jepchirchir. Weightman represented Australia in the marathon at the 2008 Summer Olympics, the 2012 Summer Olympics and the 2009 World Championships in Athletics. She won her first marathon race in 2010, setting a personal best time of 2:28:48 at the Nagano Olympic Commemorative Marathon.