| Event: | Women's 100 metre butterfly |
| Games: | 2011 |
| Venue: | Scotiabank Aquatics Center |
| Dates: | October 15 (preliminaries and finals) |
| Competitors: | 23 |
| Nations: | 17 |
| Win Value: | 58.73 |
| Win Label: | Winning score |
| Gold: | Claire Donahue |
| Goldnoc: | USA |
| Silver: | Daynara de Paula |
| Silvernoc: | BRA |
| Bronze: | Elaine Breeden |
| Bronzenoc: | USA |
| Prev: | 2007 |
| Next: | 2015 |
The women's 100 metre butterfly competition of the swimming events at the 2011 Pan American Games took place on October 15 at the Scotiabank Aquatics Center in the municipality of Zapopan, near Guadalajara, Mexico.[1] The defending Pan American Games champion was Kathleen Hersey of the United States.
The race consisted of two lengths of the pool, both lengths being in the butterfly stroke.[2]
Prior to this competition, the existing world and Pan American Games records were as follows:
| World record | 56.06 | Rome, Italy | July 27, 2009 | ||
| Pan American Games record | 59.21 | Rio de Janeiro, Brazil | July 18, 2007 |
Each National Olympic Committee (NOC) was able to enter up to two entrants providing they had met the A standard (1:03.7) in the qualifying period (January 1, 2010 to September 4, 2011). NOCs were also permitted to enter one athlete providing they had met the B standard (1:05.6) in the same qualifying period.[2]
All times are in minutes and seconds.
| KEY: | bgcolor=ccffcc align=center | q | Fastest non-qualifiers | bgcolor=ccffcc align=center | Q | Qualified | align=center | NR | National record | align=center | PB | Personal best | align=center | SB | Seasonal best | align=center | PR | Pan American Games record |
The first round was held on October 15.[3]
| Rank | Heat | Lane | Name | Nationality | Time | Notes | |||
|---|---|---|---|---|---|---|---|---|---|
| 1 | 3 | 4 | align=left | align=left | 58.59 | QA, GR | |||
| 2 | 1 | 4 | align=left | align=left | 59.23 | QA | |||
| 3 | 2 | 4 | align=left | align=left | 1:00.25 | QA | |||
| 4 | 1 | 5 | align=left | align=left | 1:01.06 | QA | |||
| 5 | 2 | 3 | align=left | align=left | 1:01.39 | QA | |||
| 6 | 3 | 1 | align=left | align=left | 1:01.41 | QA | |||
| 7 | 2 | 5 | align=left | align=left | 1:01.58 | QA | |||
| 8 | 1 | 3 | align=left | align=left | 1:01.82 | QA | |||
| 9 | 1 | 6 | align=left | align=left | 1:02.32 | QB | |||
| 10 | 3 | 5 | align=left | align=left | 1:02.86 | QB | |||
| 11 | 3 | 6 | align=left | align=left | 1:03.25 | QB | |||
| 12 | 3 | 2 | align=left | align=left | 1:03.31 | QB | |||
| 13 | 1 | 2 | align=left | align=left | 1:03.40 | QB | |||
| 14 | 3 | 3 | align=left | align=left | 1:04.14 | QB | |||
| 15 | 2 | 1 | align=left | align=left | 1:04.28 | QB | |||
| 16 | 2 | 2 | align=left | align=left | 1:04.29 | QB | |||
| 17 | 2 | 7 | align=left | align=left | 1:04.78 | ||||
| 18 | 2 | 6 | align=left | align=left | 1:05.23 | ||||
| 19 | 1 | 7 | align=left | align=left | 1:05.64 | ||||
| 20 | 3 | 7 | align=left | align=left | 1:06.16 | ||||
| 21 | 1 | 1 | align=left | align=left | 1:06.86 | ||||
| 22 | 3 | 8 | align=left | align=left | 1:08.34 | ||||
| 23 | 2 | 8 | align=left | align=left | 1:08.65 |
The B final was also held on October 15.[4]
| Rank | Lane | Name | Nationality | Time | Notes | |||
|---|---|---|---|---|---|---|---|---|
| 9 | 7 | align=left | align=left | 1:02.38 | ||||
| 10 | 4 | align=left | align=left | 1:02.51 | ||||
| 11 | 3 | align=left | align=left | 1:02.54 | ||||
| 12 | 6 | align=left | align=left | 1:02.56 | ||||
| 13 | 2 | align=left | align=left | 1:03.62 | ||||
| 14 | 8 | align=left | align=left | 1:03.63 | ||||
| 15 | 1 | align=left | align=left | 1:03.78 | ||||
| 16 | 5 | align=left | align=left | 1:06.97 |
The final was also held on October 15.[5]
| Rank | Lane | Name | Nationality | Time | Notes | |||
|---|---|---|---|---|---|---|---|---|
| 4 | align=left | align=left | 58.73 | |||||
| 3 | align=left | align=left | 59.30 | |||||
| 5 | align=left | align=left | 59.81 | |||||
| 4 | 1 | align=left | align=left | 1:00.49 | ||||
| 5 | 2 | align=left | align=left | 1:00.75 | ||||
| 6 | 6 | align=left | align=left | 1:01.11 | ||||
| 7 | 7 | align=left | align=left | 1:01.17 | ||||
| 8 | 8 | align=left | align=left | 1:01.56 |