# Swimming at the 2024 Summer Olympics – Women's 400 metre individual medley

The women's 400 metre individual medley event at the 2024 Summer Olympics was held on 29 July 2024 at Paris La Défense Arena, which was converted to a swimming pool for the swimming events. Since an Olympic size swimming pool is 50 metres long, each competitor had to swim eight lengths of the pool—two lengths with each stroke.
Canadian Summer McIntosh was the heavy favourite going into the event and ended up winning the race by over five seconds. Katie Grimes and Emma Weyant, both from the USA, took second and third, respectively. McIntosh's victory secured Canada's first-ever gold medal in the event.

## Background

Canadian Summer McIntosh won the event at the 2022 and 2023 World Championships, broke the world record in 2023 and 2024 and had a personal best over 7 seconds faster than anyone else entered into the competition. SwimSwam opined that she was "perhaps the heaviest favorite among all the individual events", and Swimming World also predicted she would win. Other contenders were the 2022 and 2023 World Championships silver medallist Katie Grimes of the USA, and 2024 World Championships winner Freya Colbert of the Great Britain. Tokyo's Olympic champion Yui Ohashi failed to qualify. Both McIntosh and Grimes were 17 years old at the time of the event.

## Qualification

Each National Olympic Committee (NOC) was permitted to enter a maximum of two qualified athletes in each individual event, but only if both of them had attained the Olympic Qualifying Time (OQT). For this event, the OQT was 4:38.53. World Aquatics then considered athletes qualifying through universality; NOCs were given one event entry for each gender, which could be used by any athlete regardless of qualification time, providing the spaces had not already been taken by athletes from that nation who had achieved the OQT. Finally, the rest of the spaces were filled by athletes who had met the Olympic Consideration Time (OCT), which was 4:39.92 for this event. In total, 15 athletes qualified through achieving the OQT, no athletes qualified through universality places and one athlete qualified through achieving the OCT.
Top 10 fastest qualification times :
| Swimmer | Country | Time | Competition |
| Summer McIntosh | Canada | 04:24:38 | 2024 Canadian Olympic Trials |
| Katie Grimes | United States | 04:31:41 | 2023 World Aquatics Championships |
| Jenna Forrester | Australia | 04:32:30 | 2023 World Aquatics Championships |
| Freya Colbert | Great Britain | 04:34:01 | 2024 Aquatics GB Swimming Championships |
| Anastasia Gorbenko | Israel | 04:34:87 | 2024 Mare Nostrum Monte Carlo |
| Vivien Jackl | Hungary | 04:34:96 | 2024 Hungarian Championships |
| Mio Narita | Japan | 04:35:40 | 2024 Japanese Olympic Trials |
| Emma Weyant | United States | 04:35:56 | 2024 United States Olympic Trials |
| Ageha Tanigawa | Japan | 04:35:60 | 2024 Japanese Olympic Trials |
| Sara Franceschi | Italy | 04:35:98 | 2023 Italian Championships |

## Heats

Two heats took place on 29 July 2024, starting at 11:00. The swimmers with the best eight times in the heats advanced to the final. Emma Weyant of the USA won the first heat and McIntosh won the second. The qualifying time was three seconds slower than it was at the Tokyo Olympics.
Results :
| Rank | Heat | Lane | Swimmer | Nation | Time | Notes |
| 1 | 1 | 6 | Emma Weyant | United States | 4:36.27 | Q |
| 2 | 1 | 4 | Katie Grimes | United States | 4:37.24 | Q |
| 3 | 2 | 4 | Summer McIntosh | Canada | 4:37.35 | Q |
| 4 | 1 | 5 | Freya Colbert | Great Britain | 4:37.62 | Q |
| 5 | 2 | 6 | Mio Narita | Japan | 4:37.84 | Q |
| 6 | 2 | 7 | Ella Ramsay | Australia | 4:39.04 | Q |
| 7 | 2 | 1 | Ellen Walshe | Ireland | 4:39.97 | Q |
| 8 | 1 | 7 | Katie Shanahan | Great Britain | 4:40.40 | Q |
| 9 | 2 | 5 | Jenna Forrester | Australia | 4:40.55 | |
| 10 | 2 | 3 | Anastasia Gorbenko | Israel | 4:41.64 | |
| 11 | 1 | 1 | Ella Jansen | Canada | 4:42.06 | |
| 12 | 2 | 8 | Emma Carrasco | Spain | 4:43.13 | |
| 13 | 2 | 2 | Ageha Tanigawa | Japan | 4:43.18 | |
| 14 | 1 | 3 | Vivien Jackl | Hungary | 4:44.47 | |
| 15 | 1 | 2 | Sara Franceschi | Italy | 4:48.89 | |
| 16 | 1 | 8 | Anja Crevar | Serbia | 4:49.16 | |

## Final

The final took place at 20:30 on 29 July. Canadian Summer McIntosh led from beginning to end, swimming ahead of the world record until 200 m and finishing over five seconds ahead of second place with a time of 4:27.71. The USA's Katie Grimes also retained second place from start to finish, while Emma Weyant of the USA progressed from fifth to third over the final 200 m to claim bronze. McIntosh's victory secured Canada's first-ever gold medal in the event. In the post race data analysis, Dominique Hérailh of SwimSwam opined that McIntosh still had room from improvement in the breaststroke and underwaters.
Results :
| Rank | Lane | Swimmer | Nation | Time |
| | 3 | Summer McIntosh | Canada | 4:27.71 |
| | 5 | Katie Grimes | United States | 4:33.40 |
| | 4 | Emma Weyant | United States | 4:34.93 |
| 4 | 6 | Freya Colbert | Great Britain | 4:35.67 |
| 5 | 7 | Ella Ramsay | Australia | 4:38.01 |
| 6 | 2 | Mio Narita | Japan | 4:38.83 |
| 7 | 8 | Katie Shanahan | Great Britain | 4:40.17 |
| 8 | 1 | Ellen Walshe | Ireland | 4:40.70 |
Statistics :
| Name | 100 metre split | 200 metre split | 300 metre split | Time | Stroke rate (strokes/min) |
| Summer McIntosh | 00:58.50 | 02:05.59 | 03:24.95 | 4:27.71 | 43.8 |
| Katie Grimes | 00:59.85 | 02:07.15 | 03:29.91 | 4:33.40 | 41.3 |
| Emma Weyant | 01:02.78 | 02:14.14 | 03:32.73 | 4:34.93 | 43.6 |
| Freya Colbert | 01:02.58 | 02:11.88 | 03:32.52 | 4:35.67 | 42.5 |
| Ella Ramsay | 01:02.79 | 02:14.66 | 03:32.96 | 4:38.01 | 40.4 |
| Mio Narita | 01:03.32 | 02:16.28 | 03:36.96 | 4:38.83 | 39.7 |
| Katie Shanahan | 01:03.38 | 02:12.75 | 03:33.85 | 4:40.17 | 37.6 |
| Ellen Walshe | 01:03.71 | 02:16.17 | 03:35.59 | 4:40.70 | 38.7 |