# Swimming at the 2023 World Aquatics Championships – Women's 400 metre individual medley

The women's 400 metre individual medley competition at the 2023 World Aquatics Championships was held on 30 July 2023.

## Records

Prior to the competition, the existing world and championship records were as follows.
| World record | Summer McIntosh (CAN) | 4:25.87 | Toronto, Canada | 1 April 2023 |
| Competition record | Katinka Hosszú (HUN) | 4:29.33 | Budapest, Hungary | 30 July 2017 |
The following new records were set during this competition.
| Date | Event | Name | Nationality | Time | Record |
| 30 July | Final | Summer McIntosh | Canada | 4:27.11 | CR |

## Results
### Heats

The heats were held at 10:32.
| Rank | Heat | Lane | Name | Nationality | Time | Notes |
| 1 | 4 | 5 | Jenna Forrester | Australia | 4:35.88 | Q |
| 2 | 4 | 4 | Summer McIntosh | Canada | 4:36.57 | Q |
| 3 | 4 | 2 | Mio Narita | Japan | 4:38.05 | Q |
| 4 | 4 | 3 | Freya Colbert | Great Britain | 4:38.29 | Q |
| 5 | 3 | 4 | Katie Grimes | United States | 4:38.39 | Q |
| 6 | 4 | 6 | Sara Franceschi | Italy | 4:38.89 | Q |
| 7 | 3 | 5 | Alex Walsh | United States | 4:39.42 | Q |
| 8 | 3 | 2 | Katie Shanahan | Great Britain | 4:39.46 | Q |
| 9 | 3 | 6 | Ageha Tanigawa | Japan | 4:40.21 | |
| 10 | 4 | 1 | Viktória Mihályvári-Farkas | Hungary | 4:41.28 | |
| 11 | 3 | 3 | Yu Yiting | China | 4:41.84 | |
| 12 | 3 | 1 | Ge Chutong | China | 4:41.87 | |
| 13 | 4 | 7 | Kiah Melverton | Australia | 4:41.96 | |
| 14 | 3 | 7 | Fantine Lesaffre | France | 4:42.07 | |
| 15 | 4 | 9 | Alba Vázquez | Spain | 4:42.11 | |
| 16 | 3 | 9 | Ellen Walshe | Ireland | 4:43.24 | |
| 17 | 4 | 0 | Ella Jansen | Canada | 4:43.35 | |
| 18 | 3 | 8 | Zsuzsanna Jakabos | Hungary | 4:43.52 | |
| 19 | 2 | 5 | Kim Seo-yeong | South Korea | 4:45.04 | |
| 20 | 4 | 8 | Cyrielle Duhamel | France | 4:45.32 | |
| 21 | 2 | 8 | Rebecca Meder | South Africa | 4:45.68 | |
| 22 | 2 | 4 | Anja Crevar | Serbia | 4:46.26 | |
| 23 | 2 | 0 | Kristen Romano | Puerto Rico | 4:48.24 | |
| 24 | 2 | 1 | Kamonchanok Kwanmuang | Thailand | 4:48.97 | |
| 25 | 2 | 7 | Xiandi Chua | Suspended Member Federation | 4:49.13 | |
| 26 | 3 | 0 | Anastasia Gorbenko | Israel | 4:49.64 | |
| 27 | 2 | 6 | Gabrielle Roncatto | Brazil | 4:49.73 | |
| 28 | 2 | 3 | Emma Carrasco | Spain | 4:50.83 | |
| 29 | 2 | 2 | Florencia Perotti | Argentina | 4:52.48 | |
| 30 | 1 | 4 | Lucero Mejia Arce | Guatemala | 5:03.52 | |
| 31 | 2 | 9 | Nicole Frank | Uruguay | 5:04.07 | |
| 32 | 1 | 3 | Chloe Cheng | Hong Kong | 5:05.72 | |
| 33 | 1 | 2 | Vivian Xhemollari | Albania | 5:11.38 | |
| 34 | 1 | 5 | Samantha van Vuure | Curaçao | 5:32.86 | |
| 35 | 1 | 6 | Meral Latheef | Maldives | 6:23.04 | |

### Final

The final was held at 21:01.
| Rank | Lane | Name | Nationality | Time | Notes |
| | 5 | Summer McIntosh | Canada | 4:27.11 | CR |
| | 2 | Katie Grimes | United States | 4:31.41 | |
| | 4 | Jenna Forrester | Australia | 4:32.30 | |
| 4 | 1 | Alex Walsh | United States | 4:34.46 | |
| 5 | 6 | Freya Colbert | Great Britain | 4:35.28 | |
| 6 | 7 | Sara Franceschi | Italy | 4:37.73 | |
| 7 | 8 | Katie Shanahan | Great Britain | 4:41.29 | |
| 8 | 3 | Mio Narita | Japan | 4:42.14 | |