Heats
mardi 1 octobre 2019, 16h30 GMT – 16h30 GMT
| Nom | Équipe | Temps | |
|---|---|---|---|
| 1 |  Sydney McLaughlin | United States | 54.45″ |
| 2 |  Amalie Iuel | Norway | + 0.27″ |
| 3 | Dalilah Muhammad | United States | + 0.42″ |
| 4 | Lea Sprunger | Switzerland | + 0.53″ |
| 5 | Anna Ryzhykova | Ukraine | + 0.66″ |
| 6 | Aminat Yusuf Jamal | Bahrain | + 0.68″ |
| 7 |  Ayomide Folorunso | Italy | + 0.75″ |
| 8 | Shiann Salmon | Jamaica | + 0.75″ |
| 9 | Rushell Clayton | Jamaica | + 0.78″ |
| 10 | Ashley Spencer | United States | + 0.83″ |
| 11 | Femke Bol | Netherlands | + 0.87″ |
| 12 | Zuzana Hejnová | Czech Republic | + 0.88″ |
| 13 |  Zurian Hechavarria | Cuba | + 0.91″ |
| 14 | Vera Rudakova | Authorised Neutral Athlete | + 1.06″ |
| 15 |  Sage Watson | Canada | + 1.12″ |
| 16 |  Hanne Claes | Belgium | + 1.23″ |
| 17 | Jessica Turner | Great Britain | + 1.27″ |
| 18 | Yadisleidis Pedroso | Italy | + 1.33″ |
| 19 |  Carolina Krafzik | Germany | + 1.48″ |
| 20 |  Joanna Linkiewicz | Poland | + 1.52″ |
| 21 | Meghan Beesley | Great Britain | + 1.52″ |
| 22 | Lauren Wells | Australia | + 1.55″ |
| 23 | Gianna Woodruff | Panama | + 1.62″ |
| 24 |  Ronda Whyte | Jamaica | + 1.92″ |
| 25 |  Sarah Carli | Australia | + 1.92″ |
| 26 |  Melissa Gonzalez | Colombia | + 2.04″ |
| 27 | Valeriya Andreyeva | Authorised Neutral Athlete | + 2.34″ |
| 28 | Linda Olivieri | Italy | + 2.37″ |
| 29 | Sara Klein | Australia | + 2.52″ |
| 30 | Yanique Haye-Smith | Turks and Caicos Islands | + 2.53″ |
| 31 | Zenéy van der Walt | South Africa | + 2.66″ |
| 32 | Paulien Couckuyt | Belgium | + 2.7″ |
| 33 | Tia-Adana Belle | Barbados | + 2.92″ |
| 34 | Jéssica Moreira | Brazil | + 3.21″ |
| 35 | Lamiae Lhabz | Morocco | + 3.99″ |
| 36 | Mariam Mamdouh Farid | Qatar | + 15.04″ |
| Kori Carter | United States | DNS | |
| Portia Bing | New Zealand | DQ | |
 Sara Slott Petersen | Denmark | DQ |