At the 2004 Summer Olympics, Hall again won the gold medal in 50 m freestyle. At 29, he became the oldest American male Olympic swimmer since Duke Kahanamoku competed at age 34 in 1924. Despite having swum the fastest 50 in the year leading up to the 2004 Games, he was regarded as a long-shot to medal in the 50 m freestyle. He also won a bronze medal for competing in the preliminary heat of the 4 × 100-meter freestyle relay.