The men's 400 metres event was part of the track and field athletics programme at the 1924 Summer Olympics.

The defending gold medalist from 1920, Bevil Rudd of South Africa, did not return; the other two medalists, silver-winning Guy Butler of Great Britain and bronze-winning Nils Engdahl of Sweden, did.

[2] Argentina, Australia, Brazil, Bulgaria, Haiti, Ireland, Mexico, Poland, and Switzerland appeared in the event for the first time.

The United States made its seventh appearance in the event, the only nation to compete in it at every Olympic Games to that point.

The top three runners in each semifinal heat advanced, making a six-man final.

(*) 440 yards (= 402.34 m) In the quarterfinals, Josef Imbach set a new Olympic record with 48.0 seconds.