Swimming at the 2015 World Aquatics Championships – Women's 400 metre freestyle
The Women's 400 metre freestyle competition of the swimming events at the 2015 World Aquatics Championships was held on 2 August with the heats and the final.Records
Prior to the competition, the existing world and championship records were as follows.
The following new records were set during this competition.
| Date | Event | Name | Nationality | Time | Record |
| 2 August | Final | Katie Ledecky | | 3:59.13 | CR |
Results
Heats
The heats were held at 11:03.
| Rank | Heat | Lane | Name | Nationality | Time | Notes |
| 1 | 5 | 4 | Katie Ledecky | | 4:01.73 | Q |
| 2 | 5 | 6 | Jessica Ashwood | | 4:04.47 | Q |
| 3 | 5 | 5 | Sharon van Rouwendaal | | 4:05.02 | Q |
| 4 | 4 | 5 | Lauren Boyle | | 4:05.53 | Q |
| 5 | 5 | 7 | Boglárka Kapás | | 4:06.21 | Q |
| 6 | 4 | 4 | Jazmin Carlin | | 4:07.15 | Q |
| 6 | 4 | 6 | Diletta Carli | | 4:07.15 | Q |
| 8 | 5 | 1 | Melania Costa | | 4:07.58 | Q |
| 9 | 5 | 3 | Cierra Runge | | 4:07.97 | |
| 10 | 4 | 9 | Anja Klinar | | 4:08.57 | |
| 11 | 5 | 8 | Shao Yiwen | | 4:08.93 | |
| 12 | 4 | 1 | Sarah Köhler | | 4:09.21 | |
| 13 | 5 | 2 | Cao Yue | | 4:09.60 | |
| 14 | 4 | 3 | Coralie Balmy | | 4:09.68 | |
| 15 | 4 | 8 | Andreina Pinto | | 4:09.75 | |
| 16 | 3 | 5 | Manuella Lyrio | | 4:10.57 | NR |
| 17 | 4 | 2 | Alice Mizzau | | 4:10.92 | |
| 18 | 3 | 4 | Arina Openysheva | | 4:11.71 | |
| 19 | 5 | 9 | Johanna Friedrich | | 4:12.09 | |
| 20 | 4 | 0 | Chihiro Igarashi | | 4:13.43 | |
| 21 | 4 | 7 | Leah Neale | | 4:13.98 | |
| 22 | 5 | 0 | Emily Overholt | | 4:14.45 | |
| 23 | 3 | 7 | Julia Hassler | | 4:14.51 | |
| 24 | 2 | 1 | Maria Alvárez | | 4:14.60 | |
| 25 | 3 | 8 | Monique Olivier | | 4:15.24 | |
| 26 | 3 | 2 | Jo Hyun-ju | | 4:15.39 | |
| 27 | 2 | 6 | Martina van Berkel | | 4:15.83 | |
| 28 | 3 | 3 | Emma Robinson | | 4:16.43 | |
| 29 | 3 | 1 | Claudia Hufnagl | | 4:17.14 | |
| 30 | 2 | 7 | Martina Elhenická | | 4:18.57 | |
| 31 | 2 | 2 | Khoo Cai Lin | | 4:18.75 | |
| 32 | 2 | 4 | Andrea Cedrón | | 4:18.96 | |
| 33 | 2 | 3 | Rachel Tseng | | 4:19.97 | |
| 34 | 3 | 6 | Samantha Arévalo | | 4:20.47 | |
| 35 | 2 | 0 | Katarina Simonović | | 4:20.94 | |
| 36 | 2 | 5 | Elisbet Gámez | | 4:21.36 | |
| 37 | 2 | 8 | Merve Eroğlu | | 4:24.77 | |
| 38 | 1 | 5 | Daniella van den Berg | | 4:24.79 | |
| 39 | 3 | 0 | Gabriela Santis | | 4:25.92 | |
| 40 | 1 | 2 | Helena Moreno | | 4:26.87 | |
| 41 | 1 | 4 | Lani Cabrera | | 4:28.31 | |
| 42 | 1 | 3 | Elena Giovannini | | 4:29.40 | |
| 43 | 1 | 6 | Sara Pastrana | | 4:32.58 | |
| 44 | 2 | 9 | Talita Te Flan | | 4:32.72 | |
| 45 | 1 | 7 | Gabriella Doueihy | | 4:35.09 | |
| 46 | 3 | 9 | Benjaporn Sriphanomthorn | | 4:36.55 | |
| 47 | 1 | 1 | Arianna Sanna | | 4:39.87 | |
| 48 | 1 | 0 | Victoria Chentsova | | 4:44.15 | |
| 49 | 1 | 8 | Makaela Holowchak | | 4:47.77 | |
Final
The final was held at 18:23.
| Rank | Lane | Name | Nationality | Time | Notes |
| 4 | Katie Ledecky | | 3:59.13 | CR |
| 3 | Sharon van Rouwendaal | | 4:03.02 | NR |
| 5 | Jessica Ashwood | | 4:03.34 | OC |
| 4 | 7 | Jazmin Carlin | | 4:03.74 | |
| 5 | 6 | Lauren Boyle | | 4:04.38 | |
| 6 | 8 | Melania Costa | | 4:06.50 | |
| 7 | 1 | Diletta Carli | | 4:07.30 | |
| 8 | 2 | Boglárka Kapás | | 4:08.22 | |
