Swimming at the 2015 World Aquatics Championships – Men's 400 metre individual medley
The 400 metre individual medley competition of the swimming events at the 2015 World Aquatics Championships was held on 9 August with the heats and the final.Records
Prior to the competition, the existing world and championship records were as follows.Results
Heats
The heats were held at 09:30.
| Rank | Heat | Lane | Name | Nationality | Time | Notes |
| 1 | 4 | 4 | Chase Kalisz | | 4:11.83 | Q |
| 2 | 4 | 3 | Dávid Verrasztó | | 4:11.99 | Q |
| 3 | 5 | 5 | Daiya Seto | | 4:12.17 | Q |
| 4 | 5 | 4 | Tyler Clary | | 4:12.22 | Q |
| 5 | 5 | 3 | Daniel Wallace | | 4:13.07 | Q |
| 6 | 5 | 7 | Jacob Heidtmann | | 4:13.62 | Q |
| 7 | 4 | 7 | Roberto Pavoni | | 4:13.91 | Q |
| 8 | 5 | 2 | Yang Zhixian | | 4:15.47 | Q |
| 9 | 4 | 2 | Federico Turrini | | 4:15.70 | |
| 10 | 4 | 5 | | | 4:15.93 | |
| 11 | 3 | 4 | Aleksandr Osipenko | | 4:16.35 | |
| 12 | 3 | 5 | Richárd Nagy | | 4:16.37 | |
| 13 | 5 | 1 | Benjámin Grátz | | 4:16.69 | |
| 14 | 4 | 8 | Gal Nevo | | 4:17.34 | |
| 15 | 5 | 8 | Kevin Wedel | | 4:17.42 | |
| 16 | 3 | 2 | Jérémy Desplanches | | 4:17.90 | NR |
| 17 | 4 | 0 | Semen Makovich | | 4:18.61 | |
| 18 | 3 | 3 | Diogo Carvalho | | 4:18.67 | |
| 19 | 5 | 6 | Huang Chaosheng | | 4:19.11 | |
| 20 | 3 | 1 | Jakub Maly | | 4:19.20 | |
| 21 | 4 | 6 | Sebastien Rousseau | | 4:20.16 | |
| 22 | 3 | 6 | Pavel Janeček | | 4:20.43 | |
| 23 | 3 | 7 | Carlos Omaña | | 4:20.74 | |
| 24 | 4 | 1 | Marc Sánchez | | 4:21.26 | |
| 25 | 1 | 4 | Henrik Christiansen | | 4:21.67 | |
| 26 | 5 | 0 | Alexis Santos | | 4:22.35 | |
| 27 | 2 | 7 | Alpkan Örnek | | 4:22.72 | |
| 28 | 5 | 9 | Nathan Capp | | 4:23.00 | |
| 29 | 1 | 5 | Ahmed Hamdy | | 4:23.02 | |
| 30 | 3 | 8 | Christoph Meier | | 4:23.57 | |
| 31 | 2 | 5 | Pedro Pinotes | | 4:23.85 | |
| 32 | 2 | 1 | Robert Žbogar | | 4:25.10 | |
| 33 | 2 | 0 | Marko Blaževski | | 4:25.57 | |
| 34 | 3 | 0 | Uvis Kalniņš | | 4:26.17 | |
| 35 | 2 | 8 | Trần Duy Khôi | | 4:27.43 | |
| 36 | 1 | 6 | Luis Vega Torres | | 4:29.57 | |
| 36 | 2 | 4 | Wen Ren-hau | | 4:29.57 | |
| 38 | 2 | 6 | Pang Sheng Jun | | 4:29.61 | |
| 39 | 2 | 2 | Nikola Dimitrov | | 4:30.78 | |
| 40 | 1 | 7 | Alvi Hjelm | | 4:33.15 | NR |
| 41 | 1 | 2 | Esteban Araya | | 4:40.23 | |
| 1 | 3 | Luis Ventura | | | DNS |
| 2 | 3 | Ahmed Mathlouthi | | | DNS |
| 2 | 9 | Christian Punter | | | DNS |
| 3 | 9 | Raphaël Stacchiotti | | | DNS |
| 4 | 9 | Thiago Simon | | | DNS |
Final
The final was held at 17:47.
| Rank | Lane | Name | Nationality | Time | Notes |
| 3 | Daiya Seto | | 4:08.50 | |
| 5 | Dávid Verrasztó | | 4:09.90 | |
| 4 | Chase Kalisz | | 4:10.05 | |
| 4 | 6 | Tyler Clary | | 4:11.71 | |
| 5 | 7 | Jacob Heidtmann | | 4:12.08 | NR |
| 6 | 2 | Daniel Wallace | | 4:13.77 | |
| 7 | 1 | Roberto Pavoni | | 4:13.81 | |
| 8 | 8 | Yang Zhixian | | 4:16.74 | |
