| POS | Rank | Heat | BIB | ATHLETE | COUNTRY | RESULTS | ms* | 
|---|---|---|---|---|---|---|---|
| 1 | 1 | 1 | 4357 | Dalilah MUHAMMAD |  USA | 54.59 Q | |
| 2 | 1 | 3 | 4047 | Ristananna Tracey |  JAM | 54.92 Q | |
| 3 | 1 | 4 | 4323 | Kori CARTER |  USA | 54.99 Q | |
| 4 | 1 | 2 | 3799 | Zuzana HEJNOVÁ |  CZE | 55.05 Q | |
| 5 | 2 | 1 | 3746 | Sage WATSON |  CAN | 55.06 Q | |
| 6 | 1 | 5 | 4239 | Lea SPRUNGER |  SUI | 55.14 Q | |
| 7 | 2 | 5 | 4048 | Ronda WHYTE |  JAM | 55.18 Q | |
| 8 | 2 | 2 | 3809 | Sara Slott PETERSEN |  DEN | 55.23 Q | |
| 9 | 3 | 5 | 4148 | Glory Onome Nathaniel |  NGR | 55.30 Q PB | |
| 10 | 3 | 1 | 3805 | Denisa Rosolová |  CZE | 55.41 Q SB | |
| 11 | 4 | 1 | 4265 | Sparkle MCKNIGHT |  TTO | 55.46 Q SB | |
| 12 | 2 | 4 | 4206 | Wenda NEL |  RSA | 55.47 Q | |
| 13 | 3 | 2 | 4375 | Cassandra TATE |  USA | 55.48 Q | |
| 14 | 3 | 4 | 3888 | Eilidh Doyle |  GBR | 55.49 Q | |
| 15 | 4 | 2 | 4009 | Ayomide FOLORUNSO |  ITA | 55.65 Q SB | |
| 16 | 2 | 3 | 4231 | Petra Fontanive |  SUI | 56.13 Q | |
| 17 | 5 | 1 | 4039 | Leah NUGENT |  JAM | 56.16 q | |
| 18 | 3 | 3 | 4351 | Shamier LITTLE |  USA | 56.18 Q | .172 | 
| 19 | 5 | 2 | 4179 | Joanna LINKIEWICZ |  POL | 56.18 q | .176 | 
| 20 | 4 | 5 | 4194 | Grace CLAXTON |  PUR | 56.35 Q | |
| 21 | 5 | 5 | 4015 | Yadisleidis PEDROSO |  ITA | 56.41 q | .401 | 
| 22 | 6 | 5 | 3882 | Meghan BEESLEY |  GBR | 56.41 q | .408 | 
| 23 | 7 | 5 | 4155 | Amalie IUEL |  NOR | 56.42 | |
| 24 | 6 | 1 | 3787 | Zurian HECHAVARRÍA |  CUB | 56.44 | |
| 25 | 7 | 1 | 3641 | Lauren BODEN |  AUS | 56.49 | |
| 26 | 4 | 4 | 4161 | Gianna WOODRUFF |  PAN | 56.50 Q | |
| 27 | 4 | 3 | 4218 | Agata ZUPIN |  SLO | 56.54 Q | |
| 28 | 5 | 3 | 4293 | Olena Kolesnychenko |  UKR | 56.88 | |
| 29 | 5 | 4 | 4007 | Marzia CARAVELLI |  ITA | 56.92 | |
| 30 | 6 | 2 | 3915 | Jessica TURNER |  GBR | 56.98 | |
| 31 | 6 | 4 | 4307 | Viktoriya TKACHUK |  UKR | 57.05 | |
| 32 | 6 | 3 | 3711 | Aminat JAMAL |  BRN | 57.41 | |
| 33 | 8 | 5 | 3733 | Noelle MONTCALM |  CAN | 57.45 | |
| 34 | 7 | 3 | 3923 | Jackie Baumann |  GER | 57.59 | |
| 35 | 7 | 2 | 4309 | Déborah RODRÍGUEZ |  URU | 57.61 SB | |
| 36 | 8 | 2 | 4232 | Yasmin GIGER |  SUI | 57.72 | |
| 37 | 7 | 4 | 3658 | Tia-Adana BELLE |  BAR | 58.82 | |
| 38 | 8 | 4 | 4115 | Drita ISLAMI |  MKD | 1:00.38 | |
| 39 | 8 | 3 | 4258 | Kristina Pronzhenko |  TJK | 1:03.44 | 
ms - Milliseconds - shown when two or more competitors finish with the same time down to hundredths of a second