Athletics at the 1968 Summer Olympics – Men's 400 metres
The men's 400 metres was an event at the 1968 Summer Olympics in Mexico City. The competition was held between 16–18 of October. Times are listed as both hand timing and automatic timing. Hand timing was the official time used in the 1968 Olympics. Fifty-five athletes from 36 nations competed. The maximum number of athletes per nation had been set at 3 since the 1930 Olympic Congress. The event was won by Lee Evans of the United States, the fourth consecutive and 11th overall title in the event by an American. The Americans swept the podium, the second time a podium sweep occurred in the men's 400 metres (the United States had previously done it in 1904, when the nation had 10 of the 12 competitors).