Heat 3
mardi 11 décembre 2018, 04h05 GMT – 04h05 GMT
| Nom | Équipe | Temps | |
|---|---|---|---|
| 1 |  Katinka Hosszú | Hungary | 4′ 23.59″ |
| 2 |  Melanie Margalis | United States | + 5.55″ |
| 3 | Sakiko Shimizu | Japan | + 7.53″ |
| 4 | Miho Takahashi | Japan | + 7.54″ |
| 5 |  Abbey Harkin | Australia | + 9.64″ |
| 6 | Min Zhou | China | + 11.75″ |
| 7 | Barbora Závadová | Czech Republic | + 13.74″ |
| 8 | Jimena Pérez | Spain | + 13.83″ |
| 9 |  Rebecca Meder | South Africa | + 15.72″ |
| 10 | Katja Fain | Slovenia | + 16.41″ |