Athletics at the 1984 Summer Olympics – Men's 400 metres
The men's 400 metres was an event at the 1984 Summer Olympics in Los Angeles, California. It was held from August 4 to August 8. Eighty athletes from 56 nations competed. The maximum number of athletes per nation had been set at 3 since the 1930 Olympic Congress. The event was won by Alonzo Babers, returning the United States to the top of the podium for the first time since 1972 (and the 13th time overall). Gabriel Tiacoh won the Ivory Coast's first Olympic medal in any event, with a silver.