Swimming at the 2011 World Aquatics Championships – Women's 100 metre butterfly
The women's 100 metre butterfly competition of the swimming events at the 2011 World Aquatics Championships took place on 24 and 25 July. The heats and semifinals took place on 24 July and the final was held on 25 July.
Records
Prior to the competition, the existing world and championship records were as follows.| Name | Nation | Time | Location | Date | |
| World record Championship record | Sarah Sjöström | 56.06 | Rome | 27 July 2009 |
Results
Heats
47 swimmers participated in 6 heats, qualified swimmers are listed:| Rank | Heat | Lane | Name | Nationality | Time | Notes |
| 1 | 5 | 5 | Dana Vollmer | Q | ||
| 2 | 6 | 4 | Alicia Coutts | Q | ||
| 3 | 4 | 5 | Jemma Lowe | Q | ||
| 4 | 4 | 2 | Jessicah Schipper | Q | ||
| 5 | 6 | 2 | Lu Ying | Q | ||
| 6 | 4 | 4 | Sarah Sjöström | Q | ||
| 7 | 4 | 3 | Ellen Gandy | Q | ||
| 7 | 5 | 6 | Jeanette Ottesen | Q | ||
| 9 | 6 | 5 | Liu Zige | Q | ||
| 10 | 5 | 4 | Christine Magnuson | Q | ||
| 11 | 5 | 3 | Inge Dekker | Q | ||
| 12 | 4 | 6 | Katerine Savard | Q | ||
| 13 | 6 | 6 | Yuka Kato | Q | ||
| 14 | 6 | 3 | Therese Alshammar | Q | ||
| 15 | 5 | 2 | Tao Li | Q | ||
| 15 | 6 | 8 | Irina Bespalova | Q | ||
| 17 | 4 | 7 | Vanessa Mohr | |||
| 17 | 4 | 8 | Sina Sutter | |||
| 19 | 2 | 3 | Otylia Jędrzejczak | |||
| 20 | 5 | 8 | Audrey Lacroix | |||
| 21 | 5 | 1 | Daynara de Paula | |||
| 22 | 6 | 7 | Kristel Vourna | |||
| 23 | 3 | 6 | Judit Ignacio Sorribes | |||
| 24 | 5 | 7 | Amit Ivry | |||
| 25 | 3 | 4 | Natsumi Hoshi | |||
| 26 | 3 | 2 | Hannah Wilson | |||
| 26 | 3 | 8 | Triin Aljand | |||
| 28 | 2 | 5 | Ingvild Snildal | |||
| 29 | 2 | 4 | Birgit Koschischek | |||
| 30 | 2 | 6 | Katarina Listopadova | |||
| 31 | 3 | 1 | Kimberly Buys | |||
| 32 | 6 | 1 | Sara Oliveira | |||
| 33 | 3 | 5 | Sara Isaković | |||
| 34 | 3 | 3 | Ilaria Bianchi | |||
| 35 | 2 | 2 | Rita Medrano | |||
| 36 | 4 | 1 | Eszter Dara | |||
| 37 | 2 | 7 | Se-Hyeon An | |||
| 38 | 2 | 1 | Iris Rosenberger | |||
| 39 | 3 | 7 | Sophia Batchelor | |||
| 40 | 1 | 4 | Jasmine Alkhaldi | |||
| 41 | 1 | 3 | Loreen Whitfield | |||
| 42 | 1 | 5 | Marie Laura Meza | |||
| 43 | 1 | 6 | Noel Borshi | |||
| 43 | 1 | 7 | Dalia Torrez | |||
| 45 | 1 | 1 | Simona Muccioli | |||
| 46 | 1 | 2 | Dorian McMenemy | |||
| 47 | 1 | 8 | Debra Daniel |
Reserve place swimoff
As two swimmers had the same time in the heats at place 17 they had to participate in a swimoff to determine the first semifinal reserve swimmer.| Rank | Lane | Name | Nationality | Time | Notes |
| 1 | 4 | Vanessa Mohr | 58.66 | ||
| 2 | 5 | Sina Sutter | 59.47 |
Semifinals
The semifinals were held on 24 July at 18:00.Semifinal 1
Semifinal 2
Final
The final was held at 18:02.| Rank | Lane | Name | Nationality | Time | Notes |
| 4 | Dana Vollmer | 56.87 | |||
| 6 | Alicia Coutts | 56.94 | |||
| 5 | Lu Ying | 57.06 | |||
| 4 | 3 | Sarah Sjöström | 57.38 | ||
| 5 | 8 | Ellen Gandy | 57.55 | ||
| 6 | 7 | Liu Zige | 57.57 | ||
| 7 | 1 | Jessicah Schipper | 57.95 | ||
| 8 | 2 | Jemma Lowe | 57.96 |