Women's 400m Semi-Final 3
mercredi 4 août 2021, 10h46 GMT – 15h46 GMT
| Nom | Temps | |
|---|---|---|
| 1 |  Stephenie Ann McPherson | 49.34″ |
| 2 |  Allyson Felix | + 0.55″ |
| 3 |  Sada Williams | + 0.77″ |
| 4 |  Natalia Kaczmarek | + 1.45″ |
| 5 |  Kyra Constantine | + 1.88″ |
| 6 |  Amandine Brossier | + 1.96″ |
| 7 | Catia Azevedo | + 1.98″ |
| 8 |  Lisanne de Witte | + 2.75″ |