# 2021 FINA World Swimming Championships (25 m) – Men's 100 metre butterfly

The Men's 100 metre butterfly competition of the 2021 FINA World Swimming Championships (25 m) was held on 17 and 18 December 2021.

## Records

Prior to the competition, the existing world and championship records were as follows.
| World record | Caeleb Dressel (USA) | 47.78 | Budapest, Hungary | 21 November 2020 |
| Competition record | Chad le Clos (RSA) | 48.08 | Windsor, Canada | 8 December 2016 |

## Results
### Heats

The heats were started on 17 December at 10:23.
| Rank | Heat | Lane | Name | Nationality | Time | Notes |
| 1 | 7 | 1 | Noè Ponti | Switzerland | 49.49 | Q, NR |
| 2 | 9 | 8 | Andrey Minakov | Russian Swimming Federation | 49.60 | Q |
| 3 | 6 | 6 | Youssef Ramadan | Egypt | 49.66 | Q, NR |
| 4 | 7 | 4 | Matteo Rivolta | Italy | 49.82 | Q |
| 5 | 9 | 1 | Nyls Korstanje | Netherlands | 49.97 | Q |
| 6 | 6 | 4 | Joshua Liendo | Canada | 50.00 | Q, NR |
| 7 | 7 | 3 | Vinicius Lanza | Brazil | 50.11 | Q |
| 8 | 5 | 3 | Dylan Carter | Trinidad and Tobago | 50.22 | Q, NR |
| 9 | 5 | 6 | Nikola Miljenić | Croatia | 50.23 | Q, NR |
| 10 | 9 | 3 | Jakub Majerski | Poland | 50.40 | Q |
| 11 | 9 | 4 | Chad le Clos | South Africa | 50.47 | Q |
| 12 | 9 | 2 | Antani Ivanov | Bulgaria | 50.49 | Q |
| 13 | 8 | 5 | Tomoe Hvas | Norway | 50.51 | Q |
| 14 | 8 | 2 | Simon Bucher | Austria | 50.53 | Q |
| 14 | 8 | 3 | Michele Lamberti | Italy | 50.53 | Q |
| 16 | 8 | 4 | Tom Shields | United States | 50.57 | Q |
| 17 | 9 | 5 | Marcin Cieślak | Poland | 50.79 | |
| 18 | 7 | 2 | José Ángel Martínez | Mexico | 50.80 | |
| 19 | 7 | 6 | Roman Shevliakov | Russian Swimming Federation | 50.87 | |
| 20 | 6 | 7 | Sun Jiajun | China | 50.92 | |
| 21 | 9 | 7 | Jan Šefl | Czech Republic | 50.99 | |
| 22 | 9 | 9 | Armin Evert Lelle | Estonia | 51.10 | |
| 23 | 8 | 6 | Grigori Pekarski | Belarus | 51.22 | |
| 24 | 5 | 2 | Adilbek Mussin | Kazakhstan | 51.23 | NR |
| 25 | 7 | 5 | Szebasztián Szabó | Hungary | 51.25 | |
| 26 | 8 | 8 | Edward Mildred | United Kingdom | 51.26 | |
| 27 | 8 | 7 | Daniel Zaitsev | Estonia | 51.30 | |
| 28 | 6 | 3 | Wang Changhao | China | 51.32 | |
| 28 | 6 | 8 | Santiago Grassi | Argentina | 51.32 | NR |
| 30 | 9 | 0 | Deividas Margevičius | Lithuania | 51.57 | |
| 31 | 5 | 9 | Sajan Prakash | India | 51.61 | NR |
| 32 | 8 | 0 | Fernando da Silva | Portugal | 51.64 | |
| 33 | 8 | 1 | Michael Andrew | United States | 51.69 | |
| 34 | 7 | 7 | Leonardo Coelho Santos | Brazil | 51.73 | |
| 35 | 8 | 9 | Brendan Hyland | Ireland | 51.79 | |
| 36 | 4 | 3 | Mehrshad Afghari | Iran | 51.87 | NR |
| 37 | 6 | 2 | Ádám Halás | Slovakia | 51.95 | |
| 38 | 7 | 9 | Louis Croenen | Belgium | 52.11 | |
| 39 | 7 | 8 | Ramon Klenz | Germany | 52.15 | |
| 40 | 6 | 1 | Moon Seung-woo | South Korea | 52.36 | |
| 41 | 5 | 5 | Navaphat Wongcharoen | Thailand | 52.50 | |
| 42 | 1 | 8 | Eldor Usmonov | Uzbekistan | 52.53 | |
| 43 | 7 | 0 | Thomas Verhoeven | Netherlands | 52.60 | |
| 44 | 6 | 9 | Thomas Piron | France | 52.66 | |
| 45 | 4 | 5 | Ben Hockin | Paraguay | 52.86 | |
| 46 | 5 | 7 | Jorge Otaiza | Venezuela | 52.93 | |
| 47 | 4 | 4 | Denys Kesil | Ukraine | 52.96 | |
| 48 | 5 | 1 | Alberto Puertas | Peru | 52.98 | |
| 49 | 5 | 4 | Waleed Abdulrazzaq | Kuwait | 53.22 | |
| 50 | 5 | 8 | Glenn Victor Sutanto | Indonesia | 53.32 | |
| 51 | 1 | 1 | Jesse Ssengonzi | Uganda | 53.64 | NR |
| 52 | 5 | 0 | Ho Tin Long | Hong Kong | 53.66 | |
| 53 | 4 | 2 | Steven Aimable | Senegal | 53.69 | |
| 54 | 3 | 1 | Carlos Vásquez | Honduras | 53.91 | NR |
| 55 | 4 | 1 | Samy Boutouil | Morocco | 53.93 | NR |
| 56 | 4 | 6 | Yousuf Al-Matrooshi | United Arab Emirates | 54.22 | |
| 57 | 3 | 6 | José Quintanilla | Bolivia | 54.38 | |
| 58 | 3 | 2 | Ramil Valizade | Azerbaijan | 54.39 | |
| 59 | 3 | 9 | Denzel González | Dominican Republic | 54.43 | NR |
| 60 | 2 | 4 | Seggio Bernardina | Curaçao | 54.45 | |
| 61 | 3 | 3 | Luis Vega Torres | Cuba | 54.46 | |
| 62 | 4 | 0 | Tomàs Lomero | Andorra | 54.48 | NR |
| 63 | 3 | 8 | Hồ Nguyễn Duy Khoa | Vietnam | 54.63 | |
| 64 | 3 | 5 | Salvador Gordo | Angola | 54.99 | |
| 65 | 4 | 9 | Ziyad Al-Salous | Jordan | 55.14 | |
| 66 | 3 | 7 | Mathieu Bachmann | Seychelles | 55.43 | |
| 67 | 1 | 6 | Mathew Bennici | Cambodia | 55.60 | NR |
| 68 | 4 | 7 | Yousif Bu Arish | Saudi Arabia | 55.65 | |
| 69 | 3 | 4 | Cherantha de Silva | Sri Lanka | 56.33 | |
| 70 | 3 | 0 | Tameea Elhamayda | Qatar | 56.61 | |
| 71 | 1 | 7 | Liam Henry | Cayman Islands | 56.62 | |
| 72 | 2 | 6 | Finau Ohuafi | Tonga | 57.13 | |
| 73 | 2 | 1 | Batmönkhiin Jürmed | Mongolia | 57.20 | |
| 74 | 2 | 2 | Johnpaul Balloqui | Gibraltar | 57.54 | |
| 75 | 2 | 3 | Collins Saliboko | Tanzania | 58.08 | |
| 76 | 2 | 7 | Belly-Cresus Ganira | Burundi | 58.48 | |
| 77 | 2 | 5 | Stefan Cvetkoski | North Macedonia | 58.91 | |
| 78 | 2 | 8 | Raekwon Noel | Guyana | 1:00.25 | |
| 79 | 1 | 5 | Kinley Lhendup | Bhutan | 1:01.07 | |
| 80 | 1 | 2 | Azhar Abbas | Pakistan | 1:02.35 | |
| 80 | 1 | 3 | Fakhriddin Madkamov | Tajikistan | 1:02.35 | |
| 82 | 2 | 9 | Tilahun Malede | Ethiopia | 1:09.15 | |
| 83 | 2 | 0 | ElhadjN'Gnane Diallo | Guinea | 1:12.52 | |
| | 4 | 8 | Philip Adejumo | Nigeria | DNS | |
| | 6 | 0 | Jaouad Syoud | Algeria | DNS | |
| | 6 | 5 | Hugo González | Spain | DNS | |
| | 9 | 6 | Teong Tzen Wei | Singapore | DNS | |
| | 1 | 4 | Mahmoud Abu Gharbieh | Palestine | DNS | |

### Semifinals

The semifinals were started on 17 December at 19:26.
| Rank | Heat | Lane | Name | Nationality | Time | Notes |
| 1 | 1 | 5 | Matteo Rivolta | Italy | 49.07 | Q |
| 2 | 2 | 7 | Chad le Clos | South Africa | 49.56 | Q |
| 3 | 2 | 5 | Youssef Ramadan | Egypt | 49.60 | Q, NR |
| 4 | 2 | 4 | Noè Ponti | Switzerland | 49.62 | Q |
| 5 | 1 | 2 | Jakub Majerski | Poland | 49.65 | Q |
| 6 | 1 | 1 | Simon Bucher | Austria | 49.70 | Q, NR |
| 7 | 1 | 8 | Tom Shields | United States | 49.76 | Q |
| 8 | 1 | 4 | Andrey Minakov | Russian Swimming Federation | 49.79 | Q |
| 9 | 1 | 6 | Dylan Carter | Trinidad and Tobago | 49.87 | NR |
| 10 | 2 | 6 | Vinicius Lanza | Brazil | 49.97 | |
| 11 | 2 | 3 | Nyls Korstanje | Netherlands | 50.11 | |
| 12 | 2 | 8 | Michele Lamberti | Italy | 50.12 | |
| 13 | 2 | 1 | Tomoe Hvas | Norway | 50.13 | |
| 14 | 1 | 3 | Joshua Liendo | Canada | 50.29 | |
| 15 | 1 | 7 | Antani Ivanov | Bulgaria | 50.30 | |
| 16 | 2 | 2 | Nikola Miljenić | Croatia | 50.58 | |

### Final

The final was held on 18 December at 18:07.
| Rank | Lane | Name | Nationality | Time | Notes |
| | 4 | Matteo Rivolta | Italy | 48.87 | |
| | 5 | Chad le Clos | South Africa | 49.04 | |
| | 8 | Andrey Minakov | Russian Swimming Federation | 49.21 | |
| 4 | 3 | Youssef Ramadan | Egypt | 49.50 | NR |
| 5 | 6 | Noè Ponti | Switzerland | 49.59 | |
| 6 | 1 | Tom Shields | United States | 49.80 | |
| 7 | 7 | Simon Bucher | Austria | 49.82 | |
| 8 | 2 | Jakub Majerski | Poland | 49.89 | |