Athletics at the 1920 Summer Olympics – Men's 400 metres
The men's 400 metres event was part of the track and field athletics programme at the 1920 Summer Olympics. The competition was held on Thursday, August 19, 1920, and on Friday, August 20, 1920. 37 runners from 16 nations competed. No nation had more than 4 runners, suggesting the limit had been reduced from the 12 maximum in force in 1908 and 1912. The event was won by Bevil Rudd of South Africa, the nation's first title (and first medal) in the event. Nils Engdahl's bronze was Sweden's first medal in the 400 metres.