On day four, Dressel ranked second overall in the prelims heats of the 100 meter freestyle with a time of 47.73 and advanced to the semifinals. The following morning of competition, he swam a 47.23 in his semifinal heat and advanced to the final ranking second for both semifinal heats. Dressel won his first individual Olympic gold medal in the final of the 100 meter freestyle with a time of 47.02, a new Olympic record. Dressel finished six hundredths of a second ahead of Australian Kyle Chalmers, which was a changing of Olympic champion from the 2016 Summer Olympics where Chalmers won the gold medal and Dressel finished sixth in the 100 meter freestyle.