The men's 100 metre freestyle event at the 1948 Olympic Games took place between 30 and 31 July at the Empire Pool.

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.

The American team, including world record holder Alan Ford, was also strong.

Cuba, Iceland, India, and Mexico each made their debut in the event.

The United States made its 10th appearance, having competed at each edition of the event to date.