Swimming at the 2003 World Aquatics Championships – Men's 100 metre backstroke
The Men's 100 Backstroke event at the 10th FINA World Aquatics Championships swam 21 - 22 July 2003 in Barcelona, Spain. Preliminary and Semifinal heats swam on July 21; the Final was held on July 22.
At the start of the event, the existing World and Championship records were:
Final
Semifinals
Preliminaries