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

The Men's 100 metre individual medley competition of the 2021 FINA World Swimming Championships (25 m) was held on 18 and 19 December 2021.

## Records

Prior to the competition, the existing world and championship records were as follows.
| World record | Caeleb Dressel (USA) | 49.28 | Budapest, Hungary | 22 November 2020 |
| Competition record | Kliment Kolesnikov (RUS) | 50.63 | Hangzhou, China | 14 December 2018 |

## Results
### Heats

The heats were started on 18 December at 09:30.
| Rank | Heat | Lane | Name | Nationality | Time | Notes |
| 1 | 5 | 5 | Daiya Seto | Japan | 51.52 | Q |
| 2 | 4 | 2 | Caio Pumputis | Brazil | 51.99 | Q |
| 3 | 3 | 3 | Finlay Knox | Canada | 52.05 | Q |
| 4 | 4 | 3 | Tomoe Hvas | Norway | 52.48 | Q |
| 5 | 5 | 4 | Marco Orsi | Italy | 52.53 | Q |
| 6 | 4 | 7 | Hwang Sun-woo | South Korea | 52.56 | Q |
| 7 | 3 | 2 | Yakov Toumarkin | Israel | 52.62 | Q |
| 7 | 3 | 4 | Kliment Kolesnikov | Russian Swimming Federation | 52.62 | Q |
| 9 | 5 | 7 | Leonardo Coelho Santos | Brazil | 52.80 | Q |
| 10 | 5 | 2 | Heiko Gigler | Austria | 52.81 | Q |
| 11 | 3 | 7 | Georgios Spanoudakis | Greece | 52.85 | Q |
| 11 | 4 | 4 | Marcin Cieślak | Poland | 52.85 | Q |
| 13 | 5 | 1 | Nic Fink | United States | 52.87 | Q |
| 14 | 4 | 6 | Bernhard Reitshammer | Austria | 52.91 | Q |
| 15 | 4 | 5 | Thomas Ceccon | Italy | 52.96 | Q |
| 16 | 3 | 5 | Andreas Vazaios | Greece | 52.98 | Q |
| 17 | 5 | 3 | Michael Andrew | United States | 53.04 | |
| 18 | 4 | 1 | Alexis Santos | Portugal | 53.08 | |
| 19 | 3 | 0 | Stan Pijnenburg | Netherlands | 53.29 | |
| 20 | 4 | 0 | Louis Croenen | Belgium | 53.32 | |
| 21 | 3 | 6 | Andrey Zhilkin | Russian Swimming Federation | 53.49 | |
| 22 | 3 | 8 | Ronny Brännkärr | Finland | 53.55 | |
| 23 | 4 | 8 | Metin Aydın | Turkey | 53.87 | |
| 24 | 3 | 9 | Berke Saka | Turkey | 53.90 | |
| 25 | 4 | 9 | Ádám Halás | Slovakia | 54.00 | |
| 26 | 2 | 7 | Balázs Holló | Hungary | 54.05 | |
| 27 | 2 | 6 | Roman Mityukov | Switzerland | 54.31 | |
| 28 | 2 | 1 | Benjamin Hockin | Paraguay | 54.70 | |
| 29 | 1 | 3 | Munzer Kabbara | Lebanon | 54.79 | NR |
| 30 | 2 | 5 | Guido Buscaglia | Argentina | 55.17 | |
| 31 | 2 | 3 | Cevin Anders Siim | Estonia | 55.40 | |
| 32 | 1 | 6 | Erick Gordillo | Guatemala | 55.45 | NR |
| 33 | 2 | 8 | Ronens Kermans | Latvia | 56.27 | |
| 34 | 2 | 0 | Ronan Wantenaar | Namibia | 56.92 | |
| 35 | 1 | 5 | Tasi Limtiaco | Federated States of Micronesia | 57.05 | |
| 36 | 1 | 2 | Nguyễn Hữu Kim Sơn | Vietnam | 57.70 | |
| 37 | 2 | 9 | Thomas Wareing | Malta | 58.33 | |
| 38 | 1 | 4 | Manuel Campo | El Salvador | 58.95 | |
| 39 | 1 | 7 | Mohamed Aan Hussain | Maldives | 1:05.20 | |
| | 2 | 2 | Maximillian Ang | Singapore | DNS | |
| | 2 | 4 | Jaouad Syoud | Algeria | DNS | |
| | 3 | 1 | José Martínez | Mexico | DNS | |
| | 5 | 0 | Mohamed Samy | Egypt | DNS | |
| | 5 | 6 | Duncan Scott | Great Britain | DNS | |
| | 5 | 8 | Markus Lie | Norway | DNS | |
| | 5 | 9 | Jan Šefl | Czech Republic | DNS | |

### Semifinals

The semifinals were started on 18 December at 18:14.
| Rank | Heat | Lane | Name | Nationality | Time | Notes |
| 1 | 1 | 6 | Kliment Kolesnikov | Russian Swimming Federation | 51.33 | Q |
| 2 | 1 | 5 | Tomoe Hvas | Norway | 51.39 | Q, NR |
| 3 | 2 | 4 | Daiya Seto | Japan | 51.52 | Q |
| 4 | 2 | 8 | Thomas Ceccon | Italy | 51.86 | Q |
| 5 | 1 | 8 | Andreas Vazaios | Greece | 51.89 | Q |
| 6 | 2 | 5 | Finlay Knox | Canada | 51.99 | Q |
| 7 | 1 | 1 | Bernhard Reitshammer | Austria | 52.03 | Q |
| 7 | 2 | 3 | Marco Orsi | Italy | 52.03 | Q |
| 9 | 1 | 3 | Hwang Sun-woo | South Korea | 52.13 | NR |
| 10 | 1 | 2 | Heiko Gigler | Austria | 52.21 | |
| 11 | 2 | 6 | Yakov Toumarkin | Israel | 52.27 | |
| 12 | 1 | 7 | Marcin Cieślak | Poland | 52.45 | |
| 12 | 2 | 2 | Leonardo Coelho Santos | Brazil | 52.45 | |
| 14 | 1 | 4 | Caio Pumputis | Brazil | 52.65 | |
| 15 | 2 | 7 | Georgios Spanoudakis | Greece | 52.85 | |
| 16 | 2 | 1 | Nic Fink | United States | 54.07 | |

### Final

The final was held on 19 December at 18:13.
| Rank | Lane | Name | Nationality | Time | Notes |
| | 4 | Kliment Kolesnikov | Russian Swimming Federation | 51.09 | |
| | 5 | Tomoe Hvas | Norway | 51.35 | NR |
| | 6 | Thomas Ceccon | Italy | 51.40 | |
| 4 | 3 | Daiya Seto | Japan | 51.46 | |
| 5 | 7 | Finlay Knox | Canada | 51.70 | NR |
| 6 | 2 | Andreas Vazaios | Greece | 51.74 | |
| 7 | 8 | Marco Orsi | Italy | 51.76 | |
| 8 | 1 | Bernhard Reitshammer | Austria | 52.16 | |