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

The Women's 100 metre butterfly competition of the 2021 FINA World Swimming Championships (25 m) was held on 20 and 21 December 2021.

## Records

Prior to the competition, the existing world and championship records were as follows.
| World record | Kelsi Dahlia (USA) | 54.59 | Eindhoven, Netherlands | 3 December 2021 |
| Competition record | Sarah Sjöström (SWE) | 54.61 | Doha, Qatar | 7 December 2014 |

## Results
### Heats

The heats were started on 20 December at 10:12.
| Rank | Heat | Lane | Name | Nationality | Time | Notes |
| 1 | 5 | 4 | Louise Hansson | Sweden | 56.04 | Q |
| 2 | 5 | 6 | Claire Curzan | United States | 56.46 | Q |
| 3 | 5 | 5 | Zhang Yufei | China | 56.47 | Q, WD |
| 4 | 3 | 5 | Torri Huske | United States | 56.59 | Q |
| 5 | 5 | 2 | Lana Pudar | Bosnia and Herzegovina | 56.87 | Q |
| 6 | 4 | 3 | Elena Di Liddo | Italy | 56.95 | Q |
| 7 | 5 | 3 | Marie Wattel | France | 57.03 | Q |
| 8 | 4 | 6 | Svetlana Chimrova | Russian Swimming Federation | 57.04 | Q |
| 9 | 4 | 2 | Maria Ugolkova | Switzerland | 57.15 | Q |
| 10 | 3 | 1 | Farida Osman | Egypt | 57.18 | Q |
| 11 | 3 | 7 | Giovanna Diamante | Brazil | 57.22 | Q |
| 12 | 4 | 1 | Katerine Savard | Canada | 57.23 | Q, WD |
| 13 | 5 | 7 | Tessa Giele | Netherlands | 57.24 | Q |
| 14 | 4 | 4 | Maggie Mac Neil | Canada | 57.32 | Q |
| 14 | 5 | 9 | Ellen Walshe | Ireland | 57.32 | Q, NR |
| 16 | 3 | 2 | Ilaria Bianchi | Italy | 57.40 | Q |
| 17 | 4 | 5 | Anastasiya Shkurdai | Belarus | 57.57 | Q |
| 18 | 3 | 3 | Anna Ntountounaki | Greece | 57.60 | Q |
| 19 | 5 | 8 | Anastasiya Kuliashova | Belarus | 57.77 | |
| 20 | 3 | 6 | Emilie Beckmann | Denmark | 57.80 | |
| 21 | 4 | 7 | Daria Klepikova | Russian Swimming Federation | 57.86 | |
| 22 | 4 | 8 | Jeong So-eun | South Korea | 58.40 | |
| 23 | 3 | 9 | María Mata | Mexico | 58.95 | |
| 24 | 3 | 8 | Yu Yiting | China | 58.96 | |
| 25 | 5 | 1 | Laura Lahtinen | Finland | 59.05 | |
| 26 | 5 | 0 | Chan Kin Lok | Hong Kong | 59.46 | |
| 27 | 2 | 4 | Luana Alonso | Paraguay | 59.68 | NR |
| 28 | 3 | 0 | Tayla Lovemore | South Africa | 1:00.20 | |
| 29 | 2 | 3 | Lê Thị Mỹ Thảo | Vietnam | 1:01.38 | NR |
| 29 | 2 | 5 | Krystal Lara | Dominican Republic | 1:01.38 | |
| 31 | 2 | 6 | Mariam Sheikhalizadeh | Azerbaijan | 1:01.96 | |
| 32 | 2 | 1 | Oumy Diop | Senegal | 1:02.51 | |
| 33 | 2 | 7 | Luna Chabat | Uruguay | 1:02.54 | |
| 34 | 2 | 8 | Karla Abarca | Nicaragua | 1:03.43 | |
| 35 | 2 | 2 | Lia Lima | Angola | 1:03.94 | |
| 36 | 2 | 9 | Antsa Rabejaona | Madagascar | 1:05.80 | |
| 37 | 2 | 0 | Sara Akasha | United Arab Emirates | 1:06.30 | |
| 38 | 1 | 2 | Mei-Li Tan Minnich | Cambodia | 1:08.68 | NR |
| 39 | 1 | 6 | Dirngulbai Misech | Palau | 1:09.42 | |
| 40 | 1 | 5 | Mineri Gomez | Guam | 1:14.43 | |
| 41 | 1 | 4 | Alyse Maniriho | Burundi | 1:29.56 | |
| | 1 | 3 | Mst Sonia Khatun | Bangladesh | DNS | |
| | 3 | 4 | Béryl Gastaldello | France | DNS | |
| | 4 | 0 | Quah Jing Wen | Singapore | DNS | |
| | 4 | 9 | Tamara Potocká | Slovakia | DNS | |

### Semifinals

The semifinals were started on 20 December at 18:32.
| Rank | Heat | Lane | Name | Nationality | Time | Notes |
| 1 | 1 | 7 | Maggie Mac Neil | Canada | 55.45 | Q |
| 2 | 1 | 4 | Claire Curzan | United States | 55.64 | Q, =WJ |
| 3 | 2 | 4 | Louise Hansson | Sweden | 55.81 | Q |
| 4 | 2 | 5 | Torri Huske | United States | 56.13 | Q |
| 5 | 2 | 3 | Elena Di Liddo | Italy | 56.21 | Q |
| 6 | 1 | 5 | Lana Pudar | Bosnia and Herzegovina | 56.28 | Q, NR |
| 7 | 2 | 8 | Anastasiya Shkurdai | Belarus | 56.42 | Q |
| 8 | 2 | 2 | Farida Osman | Egypt | 56.62 | Q |
| 9 | 2 | 1 | Ellen Walshe | Ireland | 56.68 | NR |
| 10 | 2 | 6 | Svetlana Chimrova | Russian Swimming Federation | 56.78 | |
| 11 | 1 | 8 | Anna Ntountounaki | Greece | 56.87 | |
| 12 | 1 | 2 | Giovanna Diamante | Brazil | 56.88 | |
| 12 | 2 | 7 | Tessa Giele | Netherlands | 56.88 | |
| 14 | 1 | 3 | Marie Wattel | France | 56.99 | |
| 15 | 1 | 1 | Ilaria Bianchi | Italy | 57.03 | |
| 16 | 1 | 6 | Maria Ugolkova | Switzerland | 57.42 | |

### Final

The final was held on 21 December at 19:10.
| Rank | Lane | Name | Nationality | Time | Notes |
| | 4 | Maggie Mac Neil | Canada | 55.04 | NR |
| | 3 | Louise Hansson | Sweden | 55.10 | |
| | 5 | Claire Curzan | United States | 55.39 | WJ |
| 4 | 6 | Torri Huske | United States | 55.75 | |
| 5 | 2 | Elena Di Liddo | Italy | 56.34 | |
| 6 | 1 | Anastasiya Shkurdai | Belarus | 56.37 | |
| 7 | 7 | Lana Pudar | Bosnia and Herzegovina | 56.51 | |
| 8 | 8 | Farida Osman | Egypt | 57.01 | |