Athletics at the 2007 Pan American Games – Men's 400 metres

The men's 400 metres event at the 2007 Pan American Games was held on July 23–25.

Heats
Qualification: First 3 of each heat (Q) and the next 4 fastest (q) qualified for the semifinals.

Semifinals
Qualification: First 4 of each semifinal (Q) qualified directly for the final.