These are the official results of the Men's 400 metres event at the 1996 Summer Olympics in Atlanta, Georgia which took place between 26 and 29 July. There were a total number of 64 competitors, with two non-starters.
These were the standing world and Olympic records (in seconds) prior to the 1996 Summer Olympics.
In the final Michael Johnson set a new Olympic record by 0.01 seconds with 43.49 seconds.