| Event: | Women's 100 metre butterfly |
| Competition: | 2021 FINA World Swimming Championships (25 m) |
| Venue: | Etihad Arena |
| Location: | Abu Dhabi, United Arab Emirates |
| Dates: | 20 December (heats and semifinals) 21 December (final) |
| Competitors: | 41 |
| Nations: | 35 |
| Win Value: | 55.04 |
| Gold: | Maggie Mac Neil |
| Goldnoc: | CAN |
| Silver: | Louise Hansson |
| Silvernoc: | SWE |
| Bronze: | Claire Curzan |
| Bronzenoc: | USA |
| Prev: | 2018 |
| Next: | 2022 |
The Women's 100 metre butterfly competition of the 2021 FINA World Swimming Championships (25 m) was held on 20 and 21 December 2021.[1]
Prior to the competition, the existing world and championship records were as follows.
The heats were started on 20 December at 10:12.[2]
| Rank | Heat | Lane | Name | Nationality | Time | Notes |
|---|---|---|---|---|---|---|
| 1 | 5 | 4 | 56.04 | Q | ||
| 2 | 5 | 6 | 56.46 | Q | ||
| 3 | 5 | 5 | 56.47 | Q, | ||
| 4 | 3 | 5 | 56.59 | Q | ||
| 5 | 5 | 2 | 56.87 | Q | ||
| 6 | 4 | 3 | 56.95 | Q | ||
| 7 | 5 | 3 | 57.03 | Q | ||
| 8 | 4 | 6 | 57.04 | Q | ||
| 9 | 4 | 2 | 57.15 | Q | ||
| 10 | 3 | 1 | 57.18 | Q | ||
| 11 | 3 | 7 | 57.22 | Q | ||
| 12 | 4 | 1 | 57.23 | Q, | ||
| 13 | 5 | 7 | 57.24 | Q | ||
| 14 | 4 | 4 | 57.32 | Q | ||
| 14 | 5 | 9 | 57.32 | Q, NR | ||
| 16 | 3 | 2 | 57.40 | Q | ||
| 17 | 4 | 5 | 57.57 | Q | ||
| 18 | 3 | 3 | 57.60 | Q | ||
| 19 | 5 | 8 | 57.77 | |||
| 20 | 3 | 6 | 57.80 | |||
| 21 | 4 | 7 | 57.86 | |||
| 22 | 4 | 8 | 58.40 | |||
| 23 | 3 | 9 | 58.95 | |||
| 24 | 3 | 8 | 58.96 | |||
| 25 | 5 | 1 | 59.05 | |||
| 26 | 5 | 0 | 59.46 | |||
| 27 | 2 | 4 | 59.68 | NR | ||
| 28 | 3 | 0 | ||||
| 29 | 2 | 3 | NR | |||
| 29 | 2 | 5 | ||||
| 31 | 2 | 6 | ||||
| 32 | 2 | 1 | ||||
| 33 | 2 | 7 | ||||
| 34 | 2 | 8 | ||||
| 35 | 2 | 2 | ||||
| 36 | 2 | 9 | ||||
| 37 | 2 | 0 | ||||
| 38 | 1 | 2 | NR | |||
| 39 | 1 | 6 | ||||
| 40 | 1 | 5 | ||||
| 41 | 1 | 4 | ||||
| 1 | 3 | |||||
| 3 | 4 | |||||
| 4 | 0 | |||||
| 4 | 9 |
The semifinals were started on 20 December at 18:32.[3]
| Rank | Heat | Lane | Name | Nationality | Time | Notes | |
|---|---|---|---|---|---|---|---|
| 1 | 1 | 7 | 55.45 | Q | |||
| 2 | 1 | 4 | 55.64 | Q, =WJ | |||
| 3 | 2 | 4 | 55.81 | Q | |||
| 4 | 2 | 5 | 56.13 | Q | |||
| 5 | 2 | 3 | 56.21 | Q | |||
| 6 | 1 | 5 | 56.28 | Q, NR | |||
| 7 | 2 | 8 | 56.42 | Q | |||
| 8 | 2 | 2 | 56.62 | Q | |||
| 9 | 2 | 1 | 56.68 | NR | |||
| 10 | 2 | 6 | 56.78 | ||||
| 11 | 1 | 8 | 56.87 | ||||
| 12 | 1 | 2 | 56.88 | ||||
| 12 | 2 | 7 | 56.88 | ||||
| 14 | 1 | 3 | 56.99 | ||||
| 15 | 1 | 1 | 57.03 | ||||
| 16 | 1 | 6 | 57.42 |
The final was held on 21 December at 19:10.[4]
| Rank | Lane | Name | Nationality | Time | Notes | |
|---|---|---|---|---|---|---|
| 4 | 55.04 | NR | ||||
| 3 | 55.10 | |||||
| 5 | 55.39 | WJ | ||||
| 4 | 6 | 55.75 | ||||
| 5 | 2 | 56.34 | ||||
| 6 | 1 | 56.37 | ||||
| 7 | 7 | 56.51 | ||||
| 8 | 8 | 57.01 |