Heat 4
dimanche 21 juillet 2019, 04h22 GMT – 04h22 GMT
| Nom | Équipe | Temps | |
|---|---|---|---|
| 1 |  Ariarne Titmus | Australia | 4′ 2.42″ |
| 2 |  Ajna Késely | Hungary | + 1.09″ |
| 3 |  Jianjiahe Wang | China | + 1.55″ |
| 4 |  Veronika Andrusenko | Russia | + 3.86″ |
| 5 | Kiah Melverton | Australia | + 7.14″ |
| 6 | Emma O'Croinin | Canada | + 7.26″ |
| 7 |  Mireia Belmonte | Spain | + 8.4″ |
| 8 | Julia Hassler | Liechtenstein | + 11.49″ |
| 9 | Mackenzie Padington | Canada | + 13.64″ |
| 10 | Diana Durães | Portugal | + 15.45″ |