The men's 4 × 100 metres relay event at the 1948 Olympic Games took place on August 6 & August 7.

[1] The United States team won the final, but was initially disqualified when officials thought the pass between Barney Ewell and Lorenzo Wright had taken place outside the zone.

After further review, officials saw that the pass took place inside the zone, and restored U.S. results.

Prior to the competition, the existing World and Olympic records were as follows.

The first two teams from each heat advanced to the final.