Athletics at the 2023 Pan American Games – Men's 400 metres hurdles

The men's 400 metres hurdles competition of the athletics events at the 2023 Pan American Games was held on November 1 and 3 at the Julio Martínez National Stadium of Santiago, Chile.

Records
Prior to this competition, the existing world and Pan American Games records were as follows:

Results
All times shown are in seconds.

Semifinal
Qualification: First 3 in each heat (Q) and next 2 fastest (q) qualified for the final. The results were as follows:

Final
The results were as follows: