400m dash.
Tonique Williams
She attended 10 countries. OLYMPIC GAMES 1996 Atlanta/400m----------Silver Medal 2000 Sydney/400m----------Gold Medal WORLD CHAMPIONSHIPS 1995 Gothenburg/4x400m Relay----------Bronze Medal 1997 Athens/400m----------Gold Medal 1999 Seville/400m----------Gold Medal COMMONWEALTH GAMES 1990 Auckland/4x400m----------Gold Medal 1994 Victoria/4x100m----------Silver Medal 1994 Victoria/200m----------Gold Medal 1994 Victoria/400m----------Gold Medal 2002 Manchester/4x400m----------Gold Medal
Brooke Bennett for the women and Ian Thorpe for the men. Ian was Australian and Brooke was American. Both competed in the 400 meter freestyle if that is the type of 400m you meant.
Michael Johnson
It was his second Olympic gold medal in the 400m. He successful defeated his title.
Stephanie Rice (Australia) won the gold medal in the women's 400 meter individual medley swimming event in the 2008 Summer Olympics.
It is difficult to determine who would be the most famous aboriginal athlete in the world. Arguably, it may be Cathy Freeman, who gained the world's attention with her amazing gold medal win in the 400m sprint at the Sydney Olympics in 2000.
Natalya Antyukh
Stephanie Rice
Tonique Williams
Sanya Richards-Ross