At the 2004 Summer Olympics, Hanson won a gold medal as part of the Australian 4×100-metre medley relay team by swimming the breaststroke leg in a preliminary heat (Leisel Jones swam the breaststroke leg in the final).

Several weeks later, Hanson competed at the 2004 FINA Short Course World Championships in Indianapolis, Indiana.

Most of the medal-winners from the recently finished Olympics chose not to attend which allowed Hanson to win six gold medals, five of which were for individual events.

She missed qualification for the 50- and 100-metre breaststroke events, where the three positions were claimed by Jones, Edmistone and Tarnee White respectively.

She qualified for the 200 m breaststroke and individual medley, and claimed silver in the latter event behind young teammate Stephanie Rice.