Athletics at the 2012 Summer Olympics – Men's 400 metres

Men's 400 metres at the Games of the XXX Olympiad
Venue	Olympic Stadium
Date	4–6 August
Competitors	52 from 38 nations
Winning time	43.94
Medalists
01 ! Kirani James  Grenada 02 ! Luguelin Santos  Dominican Republic 03 ! Lalonde Gordon  Trinidad and Tobago
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01 !		Kirani James	Grenada
02 !		Luguelin Santos	Dominican Republic
03 !		Lalonde Gordon	Trinidad and Tobago

The men's 400 metres competition at the 2012 Summer Olympics in London, United Kingdom, was held at the Olympic Stadium on 4–6 August.

The first round went largely to form, but defending champion Lashawn Merritt came to the meet injured and re-injured himself, unable to finish. Renny Quow also failed to start his heat. In the first race, Oscar Pistorius ran a season best to qualify. In the second heat, world champion Kirani James ran easily to win. The third heat featured three national records as Jonathan Borlée took his twin brother's mark for Belgium (Kevin also qualified in the seventh heat), Pavel Maslák set the mark for the Czech Republic and Donald Sanford set the mark for Israel. Most of the time qualifiers came from the hotly contested fourth heat, 45.61, the slowest time qualifier, though Conrad Williams got in with a 46.12 in the slow sixth heat.

It took under 45 seconds to make the final as Lalonde Gordon led the qualifiers from heat 1. Heat 2 featured James and Jonathan Borlée, and double-amputee Pistorius' attempt to make the final. But Pistorius' late charge was non-existent and he finished last in the heat. After the race, in a show of sportsmanship, James and Pistorius exchanged bib numbers, which James proudly showed as he celebrated. In the third heat, shotgun survivor Bryshon Nellum ran 45.02 for the fastest non-qualifier, leaving this the first Olympic 400 final other than the boycott year of 1980 not to have an American competitor. USA swept the medals in 2008 and 2004.