Swimming at the 2024 World Aquatics Championships – Men's 400 metre individual medley

The Men's 400 metre individual medley competition at the 2024 World Aquatics Championships was held on 18 February 2024.

Records
Prior to the competition, the existing world and championship records were as follows.

Heats
The heats were held at 09:32.

Final
The final was held at 20:01.