The women's 400 metre freestyle event at the 2025 World Aquatics Championships was held on 27 July 2025 at the World Aquatics Championships Arena at the Singapore Sports Hub in Kallang, Singapore.

Background Summer McIntosh of Canada and Katie Ledecky of the United States are the clear favorites, with the Olympic champion Ariarne Titmus absent. Titmus ended her competitive swimming career in October of that year. McIntosh holds the world record at 3:54.18, set at Canadian Trials, over two seconds faster than Ledecky’s 3:56.81 best time of 2025. Ledecky won their only head-to-head this season but trails McIntosh in recent best times.

The contest for bronze includes Lani Pallister of Australia (3:59.72), Li Bingjie of China (3:59.99), Claire Weinstein of the United States (4:00.05), and Erika Fairweather of New Zealand, a 2023 bronze medalist. Other returning finalists include Isabel Gose of Germany, Maria Fernanda Costa of Brazil, Jamie Perkins of Australia, and Yang Peiqi of China.

Qualification Each National Federation was permitted to enter a maximum of two qualified athletes in each individual event, but they could do so only if both of them had attained the "A" standard qualification time. For this event, the "A" standard qualification time was 4:10.23. Federations could enter one athlete into the event if they met the "B" standard qualification time. For this event, the "B" standard qualification time was 4:18.99. Athletes could also enter the event if they had met an "A" or "B" standard in a different event and their Federation had not entered anyone else. Additional considerations applied to Federations who had few swimmers enter through the standard qualification times. Federations in this category could at least enter two men and two women to the competition, all of whom could enter into up to two events. +Top 10 fastest qualification timesSwimmerCountryTimeCompetitionSummer McIntosh3:54.182025 Canadian TrialsAriarne Titmus3:55.442024 Australian Olympic TrialsKatie Ledecky3:56.81Fort Lauderdale stop of the 2025 TYR Pro Swim SeriesLani Pallister3:59.722025 Australian Swimming TrialsLi Bingjie3:59.992025 Chinese ChampionshipsClaire Weinstein4:00.052025 United States ChampionshipsErika Fairweather4:01.122024 Summer OlympicsPaige Madden4:02.082024 United States Olympic TrialsIsabel Gose4:02.142024 Summer OlympicsYang Peiqi4:02.532025 Chinese Championships

Records Prior to the competition, the existing world and championship records were as follows.

Heats The heats were started at 11:40.

Rank Heat Lane Name Nationality Time Notes 1 3 4 Katie Ledecky 4:01.04 Q 2 4 5 Lani Pallister 4:02.36 Q 3 3 5 Li Bingjie 4:03.11 Q 3 4 4 Summer McIntosh 4:03.11 Q 5 3 6 Yang Peiqi 4:03.36 Q 6 4 2 Jamie Perkins 4:04.39 Q 7 4 6 Isabel Marie Gose 4:05.07 Q 8 4 7 Maya Werner 4:06.75 Q 9 3 2 Maria Fernanda Costa 4:07.32 10 3 1 Sofia Diakova    Neutral Athletes B 4:08.65 11 3 7 Miyu Namba 4:08.72 12 3 0 Ichika Kajimoto 4:08.79 13 2 5 Gan Ching Hwee 4:09.81 NR 14 4 1 Eve Thomas 4:10.10 15 4 9 Francisca Martins 4:10.16 16 4 8 Gabrielle Roncatto 4:10.37 17 4 0 Ella Jansen 4:11.01 18 2 3 Park Hee-kyung 4:12.86 19 3 8 Anastasiya Kirpichnikova 4:13.92 20 3 9 Bettina Fábián 4:14.31 21 2 8 Thilda Häll 4:16.07 22 2 2 Delfina Dini 4:16.81 23 2 4 Camille Henveaux 4:16.93 24 1 4 Sasha Gatt 4:19.36 25 2 6 Batbayaryn Enkhkhüslen 4:19.80 26 2 7 María Yegres 4:20.02 27 2 1 Hannah Robertson 4:22.69 28 1 5 Kyra Rabess 4:23.08 NR 29 1 3 Jehanara Nabi 4:35.88 3 3 Erika Fairweather Disqualified 4 3 Claire Weinstein Did not start

Final The final took place at 19:33.

Rank Lane Name Nationality Time Notes 6 Summer McIntosh 3:56.26 3 Li Bingjie 3:58.21 AS 4 Katie Ledecky 3:58.49 4 5 Lani Pallister 3:58.87 5 1 Isabel Marie Gose 4:02.90 6 7 Jamie Perkins 4:03.20 7 2 Yang Peiqi 4:06.47 8 8 Maya Werner 4:09.38

References