Heat 4
dimanche 23 juillet 2017, 11h03 GMT – 11h03 GMT
| Nom | Équipe | Temps | |
|---|---|---|---|
| 1 |  Katie Ledecky | United States | 3′ 59.06″ |
| 2 |  Ariarne Titmus | Australia | + 5.2″ |
| 3 |  Boglárka Kapás | Hungary | + 6.87″ |
| 4 |  Yuhan Zhang | China | + 7.15″ |
| 5 | Veronika Andrusenko | Russia | + 7.34″ |
| 6 |  Mary-Sophie Harvey | Canada | + 10.68″ |
| 7 | Mackenzie Padington | Canada | + 10.82″ |
| 8 | Holly Hibbott | Great Britain | + 13.71″ |
| 9 | Easop Lee | Korea | + 14.88″ |
| Thi Anh Vien Nguyen | Vietnam | DNS |