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.

[1] Prior to this competition, the existing world and Pan American Games records were as follows: Qualification: First 3 in each heat (Q) and next 2 fastest (q) qualified for the final.

The results were as follows:[2] [3] [4] The results were as follows:[5]