Swimming at the 2013 World Aquatics Championships – Men's 400 metre freestyle
The men's 400 metre freestyle event in swimming at the 2013 World Aquatics Championships took place on 28 July at the Palau Sant Jordi in Barcelona, Spain.Records
Prior to this competition, the existing world and championship records were:Results
Heats
The heats were held at 10:16.
| Rank | Heat | Lane | Name | Nationality | Time | Notes |
| 1 | 5 | 4 | Sun Yang | | 3:44.67 | Q |
| 2 | 5 | 6 | Ryan Cochrane | | 3:45.74 | Q |
| 3 | 5 | 5 | Jordan Harrison | | 3:46.85 | Q |
| 4 | 3 | 4 | Kosuke Hagino | | 3:46.92 | Q |
| 5 | 5 | 7 | Devon Brown | | 3:47.17 | Q |
| 6 | 3 | 5 | Hao Yun | | 3:47.49 | Q |
| 7 | 4 | 5 | Connor Jaeger | | 3:47.83 | Q |
| 8 | 3 | 6 | James Guy | | 3:47.86 | Q |
| 9 | 3 | 3 | Robbie Renwick | | 3:47.99 | |
| 10 | 4 | 6 | Matthew Stanley | | 3:48.25 | |
| 11 | 4 | 7 | Ahmed Mathlouthi | | 3:49.45 | |
| 12 | 4 | 4 | David McKeon | | 3:49.51 | |
| 13 | 5 | 3 | Matt McLean | | 3:49.74 | |
| 14 | 4 | 2 | Gabriele Detti | | 3:49.78 | |
| 15 | 4 | 1 | Filip Zaborowski | | 3:50.22 | |
| 16 | 4 | 3 | Gergő Kis | | 3:50.87 | |
| 17 | 3 | 1 | Matias Koski | | 3:51.04 | |
| 18 | 5 | 2 | Velimir Stjepanović | | 3:51.90 | |
| 19 | 5 | 0 | David Brandl | | 3:51.98 | |
| 20 | 3 | 7 | Cristian Quintero | | 3:52.03 | |
| 21 | 2 | 3 | Richárd Nagy | | 3:53.10 | |
| 22 | 3 | 2 | Samuel Pizzetti | | 3:53.26 | |
| 23 | 5 | 8 | Ward Bauwens | | 3:53.60 | |
| 24 | 2 | 5 | Marwan Ismail | | 3:53.80 | NR |
| 25 | 5 | 1 | Serhiy Frolov | | 3:53.92 | |
| 26 | 1 | 8 | Martin Grodzki | | 3:54.47 | |
| 27 | 2 | 6 | Anton Sveinn McKee | | 3:54.67 | NR |
| 28 | 2 | 1 | Welliam Maksi | | 3:56.29 | |
| 28 | 2 | 2 | Povilas Strazdas | | 3:56.29 | |
| 30 | 4 | 9 | Jeong Jeong-Soo | | 3:56.68 | |
| 31 | 5 | 9 | Arturo Pérez Vertti | | 3:57.28 | |
| 32 | 3 | 8 | Damien Joly | | 3:57.32 | |
| 33 | 2 | 4 | Nezir Karap | | 3:57.37 | |
| 34 | 4 | 8 | Dominik Meichtry | | 3:57.65 | |
| 35 | 3 | 0 | Ihar Boki | | 3:58.27 | |
| 36 | 4 | 0 | Martin Naidich | | 3:58.92 | |
| 37 | 3 | 9 | Kevin Yeap | | 3:59.08 | |
| 38 | 1 | 4 | Nicholas Schwab | | 3:59.29 | NR |
| 39 | 2 | 7 | Marcelo Acosta Jiménez | | 4:02.21 | |
| 40 | 2 | 0 | Yeziel Morales | | 4:02.28 | |
| 41 | 2 | 9 | Matthew Lowe | | 4:03.01 | |
| 42 | 1 | 5 | Ahmed Gebrel | | 4:07.70 | |
| 43 | 2 | 8 | Phạm Thành Nguyện | | 4:13.91 | |
| 44 | 1 | 3 | Guillermo Lopéz | | 4:20.85 | |
| 45 | 1 | 7 | Sovijja Pou | | 4:22.67 | |
| 46 | 1 | 6 | Klavio Meca | | 4:27.25 | |
| 47 | 1 | 1 | Brandon Schuster | | 4:29.60 | |
| 48 | 1 | 2 | Khalid Baba | | 4:29.94 | |
Final
The final was held at 18:13.
| Rank | Lane | Name | Nationality | Time | Notes |
| 4 | Sun Yang | | 3:41.59 | |
| 6 | Kosuke Hagino | | 3:44.82 | |
| 1 | Connor Jaeger | | 3:44.85 | |
| 4 | 5 | Ryan Cochrane | | 3:45.02 | |
| 5 | 8 | James Guy | | 3:47.96 | |
| 6 | 2 | Devon Brown | | 3:48.40 | |
| 6 | 3 | Jordan Harrison | | 3:48.40 | |
| 8 | 7 | Hao Yun | | 3:48.88 | |
