The men's 100 metre freestyle was a swimming event held as part of the swimming at the 1912 Summer Olympics programme. It was the fourth appearance of the event, which had not been featured at the 1900 Games. The competition was held from Saturday July 6, 1912, to Wednesday July 10, 1912. Thirty-four swimmers from twelve nations competed. The event was won by Duke Kahanamoku of the United States, the nation's second consecutive victory in the event (tying Hungary for most all-time). Cecil Healy took silver, the only medal in the event for Australasia, the short-lived joint team of Australia and New Zealand. Another American, Ken Huszagh, took bronze.