She would occasionally compete in other track events, but 400m was her main event. Her personal best of 48.63 currently ranks her as the sixth fastest woman of all time, set while finishing second to Marie-Jose Perec's number-three time at the 1996 Olympics. She became the Olympic champion for the women's 400 metres at the 2000 Summer Olympics, at which she lit the Olympic Flame.
Freeman was the first Australian Indigenous person to become a Commonwealth Games gold medallist at age 16 in 1990. 1994 was her breakthrough season. At the 1994 Commonwealth Games in Canada, Freeman won gold in both the 200 m and 400 m. She also won the silver medal in the 1996 Olympics and came first at the 1997 World Championships, in the 400 m event. In 1998 Freeman took a break from running due to injury. She returned from injury in form with a first place in the 400 m at the 1999 World Championships. She announced her retirement from athletics in 2003.
In 2007, she founded the Cathy Freeman Foundation.