# Swimming at the 2011 World Aquatics Championships – Men's 800 metre freestyle

The men's 800 metre freestyle competition of the swimming events at the 2011 World Aquatics Championships was held on July 26 with the heats and July 27 with the final.

## Records

Prior to the competition, the existing world and championship records were as follows.
| | Name | Nation | Time | Location | Date |
| World record Championship record | Zhang Lin | China | 7:32.12 | Rome | July 29, 2009 |

## Results
### Heats

51 swimmers participated in 7 heats.
| Rank | Heat | Lane | Name | Nationality | Time | Notes |
| 1 | 7 | 4 | Sun Yang | China | 7:45.29 | Q |
| 2 | 5 | 3 | Pál Joensen | Faroe Islands | 7:45.55 | Q, NR |
| 3 | 5 | 4 | Ryan Cochrane | Canada | 7:45.57 | Q |
| 4 | 6 | 3 | Gergő Kis | Hungary | 7:48.33 | Q, NR |
| 5 | 6 | 7 | Oussama Mellouli | Tunisia | 7:48.86 | Q |
| 6 | 7 | 6 | Peter Vanderkaay | United States | 7:49.13 | Q |
| 7 | 6 | 4 | Sébastien Rouault | France | 7:49.43 | Q |
| 8 | 5 | 5 | Chad La Tourette | United States | 7:49.94 | Q |
| 9 | 6 | 5 | Samuel Pizzetti | Italy | 7:51.59 | |
| 10 | 7 | 3 | Job Kienhuis | Netherlands | 7:52.63 | |
| 11 | 6 | 2 | Mads Glæsner | Denmark | 7:54.57 | |
| 12 | 5 | 6 | Dai Jun | China | 7:54.63 | |
| 13 | 7 | 2 | Ryan Napoleon | Australia | 7:56.84 | |
| 14 | 5 | 2 | Yohsuke Miyamoto | Japan | 7:57.13 | |
| 15 | 7 | 5 | Christian Kubusch | Germany | 7:58.20 | |
| 16 | 6 | 8 | Juan Martin Pereyra | Argentina | 7:59.06 | NR |
| 17 | 6 | 6 | Federico Colbertaldo | Italy | 8:01.10 | |
| 18 | 7 | 7 | Heerden Herman | South Africa | 8:01.79 | |
| 19 | 4 | 6 | Anton Goncharov | Ukraine | 8:02.07 | |
| 20 | 5 | 1 | Mark Randall | South Africa | 8:02.45 | |
| 21 | 7 | 8 | Sergiy Frolov | Ukraine | 8:03.87 | |
| 22 | 4 | 4 | David Brandl | Austria | 8:05.66 | |
| 23 | 3 | 2 | Mateo de Angulo | Colombia | 8:05.98 | NR |
| 24 | 4 | 3 | Uladzimir Zhyharau | Belarus | 8:06.04 | |
| 25 | 5 | 7 | Gergely Gyurta | Hungary | 8:06.14 | |
| 26 | 2 | 7 | Jan Karel Petric | Slovenia | 8:07.78 | |
| 27 | 6 | 1 | Evgeny Kulikov | Russia | 8:08.54 | |
| 28 | 7 | 1 | Nikolay Bulakhov | Russia | 8:08.78 | |
| 29 | 4 | 7 | Mohamed Farhoud | Egypt | 8:10.35 | |
| 30 | 4 | 2 | Daniel Delgadillo Faisal | Mexico | 8:10.82 | |
| 31 | 4 | 8 | Jang Sang-Jin | South Korea | 8:11.94 | |
| 32 | 3 | 5 | Ricardo Monasterio | Venezuela | 8:12.16 | |
| 33 | 4 | 5 | Florian Janistyn | Austria | 8:12.90 | |
| 34 | 5 | 8 | Dylan Dunlop-Barrett | New Zealand | 8:13.06 | |
| 35 | 3 | 4 | Ventsislav Aydarski | Bulgaria | 8:13.07 | |
| 36 | 3 | 1 | Stefan Sorak | Serbia | 8:14.45 | NR |
| 37 | 3 | 6 | Christian Bayo | Puerto Rico | 8:17.02 | |
| 38 | 3 | 3 | Esteban Enderica | Ecuador | 8:17.22 | |
| 39 | 2 | 6 | Anton Sveinn McKee | Iceland | 8:17.83 | |
| 40 | 2 | 2 | Kevin Soow Choy Yeap | Malaysia | 8:18.79 | NR |
| 41 | 4 | 1 | Květoslav Svoboda | Czech Republic | 8:20.41 | |
| 42 | 3 | 7 | Ullalmath Gagan | India | 8:21.90 | NR |
| 43 | 3 | 8 | Nezir Karap | Turkey | 8:23.37 | |
| 44 | 2 | 8 | Erazmo Maršanić | Croatia | 8:23.53 | |
| 45 | 2 | 5 | Sobitjon Amilov | Uzbekistan | 8:27.35 | |
| 46 | 2 | 3 | Marko Blazevski | North Macedonia | 8:27.39 | |
| 47 | 2 | 1 | Pavol Jelenak | Slovakia | 8:28.07 | |
| 48 | 2 | 4 | Zhen Ren Teo | Singapore | 8:28.67 | |
| 49 | 1 | 5 | Iacovos Hadjiconstantinou | Cyprus | 8:38.93 | |
| 50 | 1 | 4 | Pavel Naroshkin | Estonia | 8:44.06 | |
| 51 | 1 | 3 | Heimanu Sichan | French Polynesia | 9:00.87 | |

### Final

The final was held at 18:41.
| Rank | Lane | Name | Nationality | Time | Notes |
| | 4 | Sun Yang | China | 7:38.57 | |
| | 3 | Ryan Cochrane | Canada | 7:41.86 | AR, NR |
| | 6 | Gergő Kis | Hungary | 7:44.94 | NR |
| 4 | 2 | Oussama Mellouli | Tunisia | 7:45.99 | |
| 5 | 5 | Pál Joensen | Faroe Islands | 7:46.51 | |
| 6 | 8 | Chad La Tourette | United States | 7:46.52 | |
| 7 | 7 | Peter Vanderkaay | United States | 7:46.64 | |
| 8 | 1 | Sébastien Rouault | France | 7:55.91 | |