2007 World Championships in Athletics – Men's 400 metres

The men's 400 metres at the 2007 World Championships in Athletics was held at the Nagai Stadium on 28, 29 and 31 August. The winning margin was 0.51 seconds.

Records
Prior to the competition, the established records were as follows.

Heats
Qualification: First 3 in each heat (Q) and the next 3 fastest (q) advance to the semifinals.

Semifinals
First 2 in each semifinal (Q) and the next 2 fastest (q) advance to the final.