David McCagg is an American former competition swimmer, world champion, and world record-holder.
He was in the 100 metres freestyle at the 1978 World Aquatics Championships.
McCagg was a student at Auburn University, where he swam for the Auburn Tigers swimming and diving team.
He won three gold medals at the 1978 and 1982 world championships, and another three gold medals at the 1979 Pan American Games.