The swimming competitions of the 1984 Summer Olympics were held at the McDonald's Olympic Swim Stadium, located on the University of Southern California (USC) campus. There were a total of 494 participants from 67 countries competing.
This was the first Olympic Games at which only two swimmers per country, per event, were permitted; previously, three swimmers were allowed and many countries would sweep the medal stand. In addition, the 200-metre individual medley for both men and women returned to the program from a twelve-year absence, following a proposal by the United States Olympic & Paralympic Committee (USOPC).
<nowiki>*</nowiki> Swimmers who participated in the heats only and received medals.
<nowiki>*Swimmers who participated in the heats only and received medals.</nowiki>
494 swimmers from 67 nations competed.