Semifinal 1
mercredi 2 octobre 2019, 20h05 GMT – 20h05 GMT
| Nom | Équipe | Temps | |
|---|---|---|---|
| 1 |  Dalilah Muhammad | United States | 53.91″ |
| 2 |  Sage Watson | Canada | + 0.41″ |
| 3 | Anna Ryzhykova | Ukraine | + 0.54″ |
| 4 |  Zurian Hechavarria | Cuba | + 1.12″ |
| 5 |  Hanne Claes | Belgium | + 1.34″ |
| 6 | Vera Rudakova | Authorised Neutral Athlete | + 1.66″ |
| 7 | Femke Bol | Netherlands | + 2.46″ |
| 8 | Meghan Beesley | Great Britain | + 2.98″ |