In the 2016 Olympic 4×100 m medley relay, Michael Phelps swam the butterfly leg.
The U.S. final team followed the event's fixed stroke order: Ryan Murphy led off in backstroke, Cody Miller swam breaststroke, Phelps handled butterfly, and Nathan Adrian anchored in freestyle. Phelps's split was 50.33 seconds, helping the United States finish in 3:27.95 and set an Olympic record.
The race was especially notable because it was Phelps's final Olympic event. He helped the American team win his 23rd Olympic gold medal, bringing his career total to 28 Olympic medals. The victory also extended the United States' long-running dominance in the men's Olympic medley relay.
A common mix-up is confusing the medley relay with the 4×100 m freestyle relay, in which Phelps swam a freestyle leg. In a medley relay, each swimmer uses a different stroke, and butterfly is always the third leg.