In Rio de Janeiro, Adrian won a total of four medals. He won his first medal as the anchor for the 4×100-meter freestyle relay alongside Caeleb Dressel, Michael Phelps, and Ryan Held. The Americans, with Dressel and Held as first-time Olympic competitors, finished with a time of 3:09.92, followed by France and Australia. Adrian's final leg was 46.97 seconds, the fastest of the field. In his first individual event, the 100-meter freestyle, Adrian failed to defend his Olympic title, touching third behind Kyle Chalmers and Pieter Timmers in 47.85 seconds. Adrian won another bronze medal in the 50-meter freestyle, finishing in 21.49 seconds. Another American, Anthony Ervin, won in 21.40 seconds and the defending Olympic champion Florent Manadou took second. He capped off his Olympics with another gold medal in the 4x100-meter medley relay on the final day of the competition, swimming alongside Ryan Murphy, Cody Miller, and Michael Phelps. He anchored the relay with a 46.74 split to bring home the gold in 3:27.95, a new Olympic record.