Swimming at the 2003 World Aquatics Championships

The Swimming competition of the 10th FINA World Aquatics Championships consisted of 40 long course (50m) events, swum July 20–27, 2003 in Barcelona, Spain. Swimming's 40 events were split evenly between males and females (20 each) and were:
 * freestyle (free): 50, 100, 200, 400, 800 and 1500;
 * backstroke (back): 50, 100 and 200;
 * breaststroke (breast): 50, 100 and 200;
 * butterfly (fly): 50, 100 and 200;
 * Individual Medley (IM): 200 and 400; and
 * relay: 4×100 and 4×200 freestyle, and 4×100 medley.

Men
Legend: WR – World Record; CR – Championship Record

Women
Legend: WR – World Record; CR – Championship Record