# Swimming at the 2017 World Aquatics Championships – Men's 400 metre freestyle

The Men's 400 metre freestyle competition at the 2017 World Championships was held on 23 July 2017.

## Records

Prior to the competition, the existing world and championship records were as follows.
| World record | Paul Biedermann (GER) | 3:40.07 | Rome, Italy | 26 July 2009 |
| Competition record | Paul Biedermann (GER) | 3:40.07 | Rome, Italy | 26 July 2009 |

## Results
### Heats

The heats were held at 09:43.
| Rank | Heat | Lane | Name | Nationality | Time | Notes |
| 1 | 5 | 7 | Felix Auböck | Austria | 3:44.19 | Q, NR |
| 2 | 5 | 4 | Sun Yang | China | 3:44.55 | Q |
| 3 | 6 | 6 | David McKeon | Australia | 3:45.56 | Q |
| 4 | 6 | 3 | Park Tae-hwan | South Korea | 3:45.57 | Q |
| 5 | 6 | 4 | Mack Horton | Australia | 3:45.60 | Q |
| 6 | 5 | 5 | James Guy | Great Britain | 3:45.64 | Q |
| 7 | 6 | 5 | Gabriele Detti | Italy | 3:45.72 | Q |
| 8 | 5 | 3 | Zane Grothe | United States | 3:46.14 | Q |
| 9 | 5 | 8 | Marwan El-Kamash | Egypt | 3:46.36 | NR |
| 10 | 5 | 1 | Wojciech Wojdak | Poland | 3:46.73 | |
| 11 | 6 | 7 | Henrik Christiansen | Norway | 3:46.96 | |
| 12 | 5 | 6 | Clark Smith | United States | 3:47.12 | |
| 13 | 6 | 2 | Alexander Krasnykh | Russia | 3:47.35 | |
| 14 | 6 | 8 | Filip Zaborowski | Poland | 3:47.47 | |
| 15 | 5 | 2 | Stephen Milne | Great Britain | 3:48.64 | |
| 16 | 4 | 7 | Jeremy Bagshaw | Canada | 3:48.82 | |
| 17 | 4 | 6 | Victor Johansson | Sweden | 3:48.96 | |
| 18 | 4 | 3 | Brandonn Almeida | Brazil | 3:49.61 | |
| 19 | 4 | 1 | Martin Bau | Slovenia | 3:50.75 | |
| 20 | 6 | 0 | Poul Zellmann | Germany | 3:50.88 | |
| 21 | 4 | 4 | Miguel Durán | Spain | 3:51.28 | |
| 22 | 4 | 2 | Ákos Kalmár | Hungary | 3:51.35 | |
| 23 | 5 | 0 | Anton Ipsen | Denmark | 3:51.52 | |
| 24 | 5 | 9 | Marcelo Acosta | El Salvador | 3:51.76 | |
| 25 | 6 | 9 | Qiu Ziao | China | 3:51.94 | |
| 26 | 3 | 4 | Richard Nagy | Slovakia | 3:52.10 | |
| 27 | 4 | 0 | Cristian Quintero | Venezuela | 3:53.04 | |
| 28 | 4 | 5 | Jan Micka | Czech Republic | 3:53.06 | |
| 29 | 6 | 1 | Maarten Brzoskowski | Netherlands | 3:53.17 | |
| 30 | 3 | 2 | Alin Artimon | Romania | 3:53.45 | |
| 31 | 3 | 3 | Ricardo Vargas | Mexico | 3:53.63 | |
| 32 | 2 | 6 | Khader Baqlah | Jordan | 3:54.13 | NR |
| 33 | 4 | 9 | Brent Szurdoki | South Africa | 3:54.34 | |
| 34 | 2 | 4 | Christian Bayo | Puerto Rico | 3:55.15 | |
| 35 | 3 | 7 | Martín Naidich | Argentina | 3:55.42 | |
| 36 | 3 | 6 | Mohamed Lagili | Tunisia | 3:55.47 | |
| 37 | 2 | 5 | Igor Mogne | Mozambique | 3:55.97 | NR |
| 38 | 4 | 8 | Dimitrios Dimitriou | Greece | 3:56.58 | |
| 39 | 3 | 5 | Marc Hinawi | Israel | 3:57.43 | |
| 40 | 3 | 0 | Aflah Fadlan | Indonesia | 3:58.40 | |
| 41 | 2 | 2 | Constantinos Hadjittooulis | Cyprus | 3:58.58 | |
| 42 | 3 | 8 | Wesley Roberts | Cook Islands | 3:59.29 | |
| 43 | 3 | 1 | An Ting-yao | Chinese Taipei | 3:59.57 | |
| 44 | 2 | 3 | Alex Sobers | Barbados | 4:00.50 | |
| 45 | 1 | 3 | Klavio Meça | Albania | 4:04.03 | NR |
| 46 | 3 | 9 | Irakli Revishvili | Georgia | 4:04.64 | |
| 47 | 2 | 7 | Jessie Lacuna | Philippines | 4:05.39 | |
| 48 | 1 | 4 | Mathieu Marquet | Mauritius | 4:07.28 | NR |
| 49 | 2 | 8 | Lin Sizhuang | Macau | 4:08.73 | NR |
| 50 | 2 | 1 | Felipe Tapia | Chile | 4:10.39 | |
| 51 | 1 | 5 | Abdalla Aboughazala | Qatar | 4:20.64 | |
| 52 | 2 | 0 | Mubal Ibrahim | Maldives | 4:51.57 | NR |

### Final

The final was held at 17:32.
| Rank | Lane | Name | Nationality | Time |
| | 5 | Sun Yang | China | 3:41.38 |
| | 2 | Mack Horton | Australia | 3:43.85 |
| | 1 | Gabriele Detti | Italy | 3:43.93 |
| 4 | 6 | Park Tae-hwan | South Korea | 3:44.38 |
| 5 | 4 | Felix Auböck | Austria | 3:45.21 |
| 6 | 7 | James Guy | Great Britain | 3:45.58 |
| 7 | 8 | Zane Grothe | United States | 3:45.86 |
| 8 | 3 | David McKeon | Australia | 3:46.27 |