The Men's 100 metre butterfly competition at the 2024 World Aquatics Championships was held on 16 and 17 February 2024.

[1][2] Prior to the competition, the existing world and championship records were as follows.

[3] The heats were started on 16 February at 09:31.

[5] The semifinals were held on 16 February at 19:09.

[6] The final was held on 17 February at 19:42.