On day four of competition, Wednesday June 16, 2021, Dressel ranked 5th out of all prelims heats in the 100 meter freestyle swimming a 48.25 and advancing to the semifinals. In the semifinals in the evening of the same day, Dressel ranked first with a time of 47.77 and advanced to the final. On day five, June 17, 2021, Dressel won the 100 m freestyle with a time of 47.39 and qualifying him for the US Olympic Swimming team in the 100 m freestyle and the 4×100 m freestyle relay for the 2020 Summer Olympics. He tied the US Open record and Championships record for the 100 meter freestyle with his swim. This marked the second Olympic Games Dressel qualified to compete at.