Brooke first represented Australia at the age of 16 during the 1994 Commonwealth Games in Victoria, Canada placing fourth in 200m breaststroke. She continued representing Australia for a decade winning multiple medals at World Championships, World Swimming Championships (25m), Swimming World Cups and Commonwealth Games. 

In 2004, Brooke reached her Olympic dream, winning gold in the 4 x 100 medley relay and silver for the 100m breaststroke at the Athens 2004 Olympics. 

Brooke Hanson received the Medal of the Order of Australia in 2005 for her contribution to swimming and has been a Starlight Ambassador since 2022.