The men's 100 metre butterfly event at the 2024 Summer Olympics was held from 2 to 3 August 2024 at Paris La Défense Arena.

[2] Going into the event, Canada's Josh Liendo was ranked number one in the world, having swum a 50.06 at the Canadian Olympic Trials.

Other contenders who had swum under 51 seconds in 2024 were: Hungarian Hubert Kós, Dutchman Nyls Korstanje, Katsuhiro Matsumoto of Japan, Jakub Majerski of Poland, Gal Cohen Groumi of Israel and Thomas Heilman of the USA.

[7][8] Finally, the rest of the spaces were filled by athletes who had met the Olympic Consideration Time (OCT), which was 51.93 for this event.

[16] SwimSwam speculated that is poor performance could have been due to having already swum three races that day, including the final of the 50 metre freestyle 30 minutes earlier.

[19] Milák won with a time of 49.90;[15][20] he was fifth at the halfway turn but finished with the fastest closing 50 metres split to win gold.

Canada's Ilya Kharun had the second fastest closing 50 metres split, which elevated him from seventh at halfway to third at the finish, winning him the bronze.

[21] Grousset was third at the 50 metre mark, but performed a slow turn compared to the rest of the field which SwimSwam later opined may have cost him third place.