The men's 100 metre butterfly event at the 2025 World Aquatics Championships was held from 1 to 2 August 2025 at the World Aquatics Championships Arena at the Singapore Sports Hub in Kallang, Singapore.

Background The event did not feature world record holder Caeleb Dressel or European record holder Kristóf Milák, but the field included 14 swimmers with lifetime bests under 51 seconds. Maxime Grousset of France led the 2024–25 season rankings, having improved his national record to 50.11 at the 2025 French Elite Championships. Canada’s Ilya Kharun and Josh Liendo ranked third and fourth in 2025 with 50.37 and 50.46, respectively; Liendo was the 2024 Olympic silver medalist and Canadian record holder with 49.99. Switzerland’s Noè Ponti, fourth at the Olympics, had a 2025 best of 50.27. Other notable competitors included Hubert Kós of Hungary, Nyls Korstanje of the Netherlands, and Shaine Casas of the United States, all ranked among the top six this season.

Qualification Each National Federation was permitted to enter a maximum of two qualified athletes in each individual event, but they could do so only if both of them had attained the "A" standard qualification time. For this event, the "A" standard qualification time was 51.77. Federations could enter one athlete into the event if they met the "B" standard qualification time. For this event, the "B" standard qualification time was 53.58. Athletes could also enter the event if they had met an "A" or "B" standard in a different event and their Federation had not entered anyone else. Additional considerations applied to Federations who had few swimmers enter through the standard qualification times. Federations in this category could at least enter two men and two women to the competition, all of whom could enter into up to two events. +Top 10 fastest qualification timesSwimmerCountryTimeCompetitionKristóf Milák49.902024 Summer OlympicsJosh Liendo49.992024 Summer OlympicsMaxime Grousset50.112025 French EliteNoè Ponti50.162024 Swiss ChampionshipsCaeleb Dressel50.192024 United States Olympic TrialsIlya Kharun50.372025 Canadian TrialsShaine Casas50.512025 United States ChampionshipsHubert Kós50.552025 Hungarian ChampionshipsNyls Korstanje50.59Olympic Games Paris 2024Matthew Temple50.612024 New South Wales Championships

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

Heats The heats took place on 1 August at 10:02.

RankHeatLaneSwimmerNationTimeNotes 1 6 4 Noè Ponti 50.68 Q 2 8 5 Ilya Kharun 50.70 Q 3 8 6 Andrey Minakov    Neutral Athletes B 50.93 Q 4 7 3 Matthew Temple 50.97 Q 5 8 4 Josh Liendo 51.04 Q 6 7 1 Simon Bucher 51.16 Q, NR 7 8 7 Jesse Coleman 51.20 Q 8 7 6 Katsuhiro Matsumoto 51.30 Q 9 8 9 Diogo Ribeiro 51.34 Q 10 6 6 Jakub Majerski 51.35 Q 11 6 0 Edward Mildred 51.36 Q 11 7 4 Maxime Grousset 51.36 Q 11 8 1 Thomas Ceccon 51.36 Q 14 6 2 Naoki Mizunuma 51.44 Q 15 8 8 Gal Cohen Groumi 51.46 Q 16 7 2 Clément Secchi 51.58 Q 17 8 0 Federico Burdisso 51.59 18 5 2 Denis Popescu 51.61 19 7 5 Shaine Casas 51.66 20 8 3 Nyls Korstanje 51.67 21 7 0 Ksawery Masiuk 51.79 22 7 9 Adilbek Mussik 51.87 23 6 8 Xu Fang 51.90 24 6 9 Quah Zheng Wen 51.92 25 8 2 Chen Juner 51.95 26 6 3 Thomas Heilman 52.02 27 7 7 Luca Armbruster 52.05 28 7 8 Casper Puggaard 52.22 29 6 1 Josha Salchow 52.24 30 6 7 Mikhail Antipov    Neutral Athletes B 52.26 31 4 6 Eldor Usmonov 52.46 32 5 5 Ulises Cazau 52.60 33 5 8 Konstantinos Stamou 52.81 34 4 2 Jack Cassin 52.84 35 4 4 Grigori Pekarski    Neutral Athletes A 52.90 36 5 4 Vili Sivec 53.01 37 5 6 Alex Ahtiainen 53.04 38 4 7 Denys Kesil 53.05 39 5 3 Arbidel González 53.12 40 5 7 Jorge Iga 53.14 41 3 3 Jesse Ssengonzi 53.32 NR 42 3 4 Josh Kirlew 53.68 43 3 2 Samuel Kostal 53.69 44 4 3 Miloš Milenković 53.74 45 3 6 Raekwon Noel 53.91 NR 45 5 9 Jorge Otaiza 53.91 47 5 0 Benedicton Rohit Beniston Manickaraj 53.92 48 3 7 Oscar Peyre Mitilla 54.44 49 4 8 Birnir Freyr Hálfdánarson 54.59 50 4 1 Navaphat Wongcharoen 54.76 51 3 1 Esteban Nuñez 54.82 52 4 0 Luka Jovanović 54.84 53 2 4 Zackary Gresham 55.46 54 3 8 Ramil Valizada 55.53 55 3 9 Julien Henx 55.57 56 1 1 Victor Ah Yong 55.76 NR 57 1 2 Yousif Bu Arish 55.99 58 3 0 Antoine Destang 56.19 59 4 9 Nika Tchitchiashvili 56.42 60 1 6 Lucas de los Santos 56.53 61 2 3 Kaio Faftine 56.86 62 2 5 Sebastián Serafeim 56.88 63 1 4 Lam Chi Chong 57.50 64 2 1 Stephen Nyoike 57.51 65 2 8 Israel Poppe 57.96 66 2 2 Mohammad Al-Otaibi 58.09 67 1 7 Salem Sabt 58.10 68 2 0 Jefferson Kpanou 58.16 69 2 6 Collins Saliboko 58.43 70 2 9 Kokoro Frost 58.82 71 2 7 Mohamad Masoud 59.01 72 1 0 Clinton Opute 59.29 73 1 3 Naeem de Souza 74 1 8 Lin Myat Thu 75 1 5 Charlie Gibbons 3 5 Abeku Jackson 4 5 Bryan Leong 5 1 Tajus Juska 6 5 Hubert Kós

Semifinals Semifinals took place on 1 August at 19:10.

RankHeatLaneSwimmerNationTimeNotes 1 2 4 Noè Ponti 50.18 Q 2 2 3 Josh Liendo 50.24 Q 3 1 7 Maxime Grousset 50.25 Q 4 1 4 Ilya Kharun 50.39 Q 5 2 1 Thomas Ceccon 50.42 Q, NR 6 1 5 Matthew Temple 50.83 Q 7 2 5 Andrey Minakov    Neutral Athletes B 50.87 Q 8 1 3 Simon Bucher 50.88 Q, NR 9 1 1 Naoki Mizunuma 50.96 10 2 6 Jesse Coleman 51.14 11 1 6 Katsuhiro Matsumoto 51.20 12 2 2 Diogo Ribeiro 51.21 13 1 8 Clément Secchi 51.23 14 1 2 Jakub Majerski 51.40 15 2 7 Edward Mildred 51.61 16 2 8 Gal Cohen Groumi 51.64

Final The final took place on 2 August at 19:43.

Rank Lane Name Nationality Time Notes 3 Maxime Grousset 49.62 ER 4 Noè Ponti 49.83 NR 6 Ilya Kharun 50.07 4 5 Josh Liendo 50.09 5 7 Matthew Temple 50.57 6 1 Andrei Minakov    Neutral Athletes B 50.90 7 8 Simon Bucher 50.92 8 2 Thomas Ceccon 51.12

References