Women's 400m Round 1 - Heat 1
mardi 3 août 2021, 00h45 GMT – 05h45 GMT
| Nom | Temps | |
|---|---|---|
| 1 |  Shaunae Miller-Uibo | 50.5″ |
| 2 |  Roxana Gomez | + 0.26″ |
| 3 |  Sada Williams | + 0.86″ |
| 4 | Aliyah Abrams | + 0.94″ |
| 5 |  Kyra Constantine | + 1.19″ |
| 6 | Anita Horvat | + 1.84″ |
| 7 |  Patience Okon George | + 1.91″ |