| Event: | Women's 800 metre freestyle |
| Competition: | 2011 World Aquatics Championships |
| Dates: | July 29, 2011 (heats) July 30, 2011 (final) |
| Competitors: | 34 |
| Nations: | 28 |
| Win Value: | 8:17.51 |
| Gold: | Rebecca Adlington |
| Goldnoc: | GBR |
| Silver: | Lotte Friis |
| Silvernoc: | DEN |
| Bronze: | Kate Ziegler |
| Bronzenoc: | USA |
| Prev: | 2009 |
| Next: | 2013 |
The women's 800 metre freestyle competition of the swimming events at the 2011 World Aquatics Championships was held on July 29 with the heats and July 30 with the final.
Prior to the competition, the existing world and championship records were as follows.
| Name | Nation | Time | Location | Date | |||
|---|---|---|---|---|---|---|---|
| World record | Rebecca Adlington | align=left | 8:14.10 | Beijing | August 16, 2008 | ||
| Championship record | Lotte Friis | align=left | 8:15.92 | Rome | August 1, 2009 |
32 swimmers participated in 5 heats.[1]
| Rank | Heat | Lane | Name | Nationality | Time | Notes | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 5 | 4 | 8:22.27 | Q | ||||||||||
| 2 | 5 | 5 | 8:23.07 | Q | ||||||||||
| 3 | 3 | 5 | 8:27.72 | Q | ||||||||||
| 4 | 4 | 4 | 8:28.28 | Q | ||||||||||
| 5 | 3 | 4 | 8:28.35 | Q | ||||||||||
| 6 | 3 | 7 | 8:28.40 | Q | ||||||||||
| 7 | 5 | 1 | 8:28.50 | Q, NR | ||||||||||
| 8 | 3 | 6 | 8:28.75 | Q | ||||||||||
| 9 | 3 | 2 | 8:28.76 | |||||||||||
| 10 | 4 | 5 | 8:29.05 | |||||||||||
| 11 | 5 | 2 | 8:29.13 | |||||||||||
| 12 | 5 | 7 | 8:29.16 | |||||||||||
| 13 | 4 | 7 | 8:30.00 | |||||||||||
| 14 | 4 | 6 | 8:32.35 | - | 15 | 4 | 1 | 8:33.62 | ||||||
| 16 | 5 | 6 | 8:34.33 | |||||||||||
| 17 | 3 | 3 | 8:35.17 | |||||||||||
| 18 | 4 | 8 | 8:41.93 | |||||||||||
| 19 | 5 | 3 | 8:42.15 | |||||||||||
| 20 | 2 | 4 | 8:42.65 | |||||||||||
| 21 | 3 | 8 | 8:43.89 | |||||||||||
| 22 | 5 | 8 | 8:44.01 | |||||||||||
| 23 | 2 | 5 | 8:45.86 | |||||||||||
| 24 | 2 | 2 | 8:46.00 | NR | ||||||||||
| 25 | 3 | 1 | 8:51.93 | |||||||||||
| 26 | 2 | 6 | 8:57.17 | |||||||||||
| 27 | 2 | 3 | 9:00.04 | |||||||||||
| 28 | 1 | 6 | 9:00.96 | |||||||||||
| 29 | 1 | 5 | 9:01.84 | |||||||||||
| 30 | 1 | 4 | 9:02.28 | NR | ||||||||||
| 31 | 2 | 7 | 9:08.40 | |||||||||||
| 32 | 1 | 3 | 9:12.47 | |||||||||||
| – | 4 | 2 | DNS | |||||||||||
| – | 4 | 3 | DNS |
The final was held at 19:30.[2]
| Rank | Lane | Name | Nationality | Time | Notes | |
|---|---|---|---|---|---|---|
| 4 | 8:17.51 | |||||
| 5 | 8:18.20 | |||||
| 6 | 8:23.36 | |||||
| 4 | 3 | 8:24.05 | ||||
| 5 | 7 | 8:24.79 | NR | |||
| 6 | 2 | 8:29.20 | ||||
| 7 | 8 | 8:30.45 | ||||
| 8 | 1 | 8:32.72 |