The men's 100 metre freestyle event at the 1948 Olympic Games took place between 30 and 31 July at the Empire Pool. There were 41 competitors from 19 nations. Nations had been limited to three swimmers each since the 1924 Games. The event was won by Wally Ris, returning the United States to the podium in the event after a one-Games absence broke a seven-Games streak. It was the sixth victory for an American in the 100 metre freestyle, most of any nation. Another American, Alan Ford, took silver. Géza Kádas of Hungary earned bronze, the nation's third medal in four Games. Japan's three-Games medal streak in the event ended with no Japanese swimmers competing due to the nation not being invited after World War II.