| Event: | Women's 400 metre individual medley |
| Games: | 2020 Summer |
| Venue: | Tokyo Aquatics Centre |
| Dates: | 24 July 2021 (heats) 25 July 2021 (final) |
| Competitors: | 17 |
| Nations: | 13 |
| Win Value: | 4:32.08 |
| Gold: | Yui Ohashi |
| Goldnoc: | JPN |
| Silver: | Emma Weyant |
| Silvernoc: | USA |
| Bronze: | Hali Flickinger |
| Bronzenoc: | USA |
| Prev: | 2016 |
| Next: | 2024 |
The women's 400 metre individual medley event at the 2020 Summer Olympics was held on 24 and 25 July 2021 at the Tokyo Aquatics Centre.[1] It was the event's fifteenth consecutive appearance, having been held at every edition since 1964.
Japan's home favourite Yui Ohashi held off a late charge from the U.S.' Emma Weyant to win her nation's first Olympic title in the event (she would go on to win gold in the 200 m medley as well). Second at the halfway mark, Ohashi used a stunning breaststroke leg to separate herself from the tight field and touch in 4:32.08 for gold. Meanwhile, Weyant, 1.99 seconds behind Ohashi heading into the freestyle, stormed home to take silver in 4:32.76. Weyant's teammate Hali Flickinger moved through the field in the final lap to win bronze more than two seconds behind in 4:34.90.
Spain's defending bronze medallist Mireia Belmonte (4:35.13) could not repeat her podium efforts from Rio five years earlier and settled for fourth. In the hunt for a medal, Hungary's defending champion Katinka Hosszú faded down the stretch to take fifth in 4:35.98, almost 10 seconds off her world record set at the last Games. Hosszú's teammate Viktória Mihályvári-Farkas (4:37.75) took sixth, while Great Britain's Aimee Willmott (4:38.30) repeated her seventh-place finish from Rio five years earlier. Outside the sub 4:40 club, Italy's Ilaria Cusinato (4:40.65) rounded out the championship field.
Prior to this competition, the existing world and Olympic records were as follows.
No new records were set during the competition.
See main article: Swimming at the 2020 Summer Olympics – Qualification. The Olympic Qualifying Time for the event is 4:38.53. Up to two swimmers per National Olympic Committee (NOC) can automatically qualify by swimming that time at an approved qualification event. The Olympic Selection Time is 4:46.89. Up to one swimmer per NOC meeting that time is eligible for selection, allocated by world ranking until the maximum quota for all swimming events is reached. NOCs without a female swimmer qualified in any event can also use their universality place.[2]
The competition consists of two rounds: heats and a final. The swimmers with the best 8 times in the heats advance to the final. Swim-offs are used as necessary to break ties for advancement to the next round.[3]
All times are Japan Standard Time (UTC+9)[1]
| Date | Time | Round | |
|---|---|---|---|
| 24 July | 20:05 | Heats | |
| 25 July | 11:12 | Final |
The swimmers with the top 8 times, regardless of heat, advance to the final.[4]
| Rank | Heat | Lane | Swimmer | Nation | Time | Notes | |||
|---|---|---|---|---|---|---|---|---|---|
| 1 | 3 | 5 | 4:33.55 | ||||||
| 2 | 3 | 6 | 4:35.28 | ||||||
| 3 | 2 | 4 | 4:35.71 | ||||||
| 4 | 3 | 3 | 4:35.88 | ||||||
| 5 | 2 | 5 | 4:35.98 | ||||||
| 6 | 2 | 6 | 4:35.99 | ||||||
| 7 | 3 | 4 | 4:36.01 | ||||||
| 8 | 2 | 7 | 4:37.37 | ||||||
| 9 | 3 | 2 | 4:39.93 | ||||||
| 10 | 3 | 1 | 4:40.50 | ||||||
| 11 | 2 | 1 | 4:41.64 | ||||||
| 12 | 3 | 8 | 4:41.76 | ||||||
| 13 | 3 | 7 | 4:41.98 | ||||||
| 14 | 2 | 2 | 4:44.54 | ||||||
| 15 | 1 | 5 | 4:44.66 | ||||||
| 16 | 1 | 3 | 4:54.54 | ||||||
| 17 | 1 | 4 | 5:01.98 | ||||||
| data-sort-value=18 | — | 2 | 3 | data-sort-value=9:99.99 |
| Rank | Lane | Swimmer | Nation | Time | Notes | |
|---|---|---|---|---|---|---|
| 3 | 4:32.08 | |||||
| 4 | 4:32.76 | |||||
| 2 | 4:34.90 | |||||
| 4 | 6 | 4:35.13 | ||||
| 5 | 1 | 4:35.98 | ||||
| 6 | 7 | 4:37.75 | ||||
| 7 | 5 | 4:38.30 | ||||
| 8 | 8 | 4:40.65 |