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.Results
Heats
The heats were held at 09:43.
| Rank | Heat | Lane | Name | Nationality | Time | Notes |
| 1 | 5 | 7 | | | 3:44.19 | Q, NR |
| 2 | 5 | 4 | Sun Yang | | 3:44.55 | Q |
| 3 | 6 | 6 | | | 3:45.56 | Q |
| 4 | 6 | 3 | Park Tae-hwan | | 3:45.57 | Q |
| 5 | 6 | 4 | | | 3:45.60 | Q |
| 6 | 5 | 5 | | | 3:45.64 | Q |
| 7 | 6 | 5 | | | 3:45.72 | Q |
| 8 | 5 | 3 | | | 3:46.14 | Q |
| 9 | 5 | 8 | | | 3:46.36 | NR |
| 10 | 5 | 1 | | | 3:46.73 | |
| 11 | 6 | 7 | | | 3:46.96 | |
| 12 | 5 | 6 | | | 3:47.12 | |
| 13 | 6 | 2 | | | 3:47.35 | |
| 14 | 6 | 8 | | | 3:47.47 | |
| 15 | 5 | 2 | | | 3:48.64 | |
| 16 | 4 | 7 | | | 3:48.82 | |
| 17 | 4 | 6 | | | 3:48.96 | |
| 18 | 4 | 3 | | | 3:49.61 | |
| 19 | 4 | 1 | | | 3:50.75 | |
| 20 | 6 | 0 | | | 3:50.88 | |
| 21 | 4 | 4 | | | 3:51.28 | |
| 22 | 4 | 2 | | | 3:51.35 | |
| 23 | 5 | 0 | | | 3:51.52 | |
| 24 | 5 | 9 | | | 3:51.76 | |
| 25 | 6 | 9 | Qiu Ziao | | 3:51.94 | |
| 26 | 3 | 4 | | | 3:52.10 | |
| 27 | 4 | 0 | | | 3:53.04 | |
| 28 | 4 | 5 | | | 3:53.06 | |
| 29 | 6 | 1 | | | 3:53.17 | |
| 30 | 3 | 2 | | | 3:53.45 | |
| 31 | 3 | 3 | | | 3:53.63 | |
| 32 | 2 | 6 | | | 3:54.13 | NR |
| 33 | 4 | 9 | | | 3:54.34 | |
| 34 | 2 | 4 | | | 3:55.15 | |
| 35 | 3 | 7 | | | 3:55.42 | |
| 36 | 3 | 6 | | | 3:55.47 | |
| 37 | 2 | 5 | | | 3:55.97 | NR |
| 38 | 4 | 8 | | | 3:56.58 | |
| 39 | 3 | 5 | | | 3:57.43 | |
| 40 | 3 | 0 | | | 3:58.40 | |
| 41 | 2 | 2 | | | 3:58.58 | |
| 42 | 3 | 8 | | | 3:59.29 | |
| 43 | 3 | 1 | An Ting-yao | | 3:59.57 | |
| 44 | 2 | 3 | | | 4:00.50 | |
| 45 | 1 | 3 | | | 4:04.03 | NR |
| 46 | 3 | 9 | | | 4:04.64 | |
| 47 | 2 | 7 | | | 4:05.39 | |
| 48 | 1 | 4 | | | 4:07.28 | NR |
| 49 | 2 | 8 | Lin Sizhuang | | 4:08.73 | NR |
| 50 | 2 | 1 | | | 4:10.39 | |
| 51 | 1 | 5 | | | 4:20.64 | |
| 52 | 2 | 0 | | | 4:51.57 | NR |
Final
The final was held at 17:32.
