| POS | BIB | ATHLETE | COUNTRY | MARK | Reaction Time | 
|---|---|---|---|---|---|
| 1 | 1131 | Shaunae MILLER-UIBO |  BAH | 50.50 Q | 0.132 | 
| 2 | 1583 | Roxana GÓMEZ |  CUB | 50.76 Q =PB | 0.182 | 
| 3 | 1151 | Sada WILLIAMS |  BAR | 51.36 Q SB | 0.154 | 
| 4 | 2249 | Aliyah ABRAMS |  GUY | 51.44 q SB | 0.160 | 
| 5 | 1388 | Kyra CONSTANTINE |  CAN | 51.69 q | 0.167 | 
| 6 | 3462 | Anita HORVAT |  SLO | 52.34 | 0.185 | 
| 7 | 3046 | Patience Okon GEORGE |  NGR | 52.41 | 0.187 | 
| POS | BIB | ATHLETE | COUNTRY | MARK | Reaction Time | 
|---|---|---|---|---|---|
| 1 | 2033 | Jodie WILLIAMS |  GBR | 50.99 Q | 0.170 | 
| 2 | 3853 | Quanera HAYES |  USA | 51.07 Q | 0.175 | 
| 3 | 3223 | Cátia AZEVEDO |  POR | 51.26 Q | 0.155 | 
| 4 | 2991 | Lisanne DE WITTE |  NED | 51.68 q SB | 0.172 | 
| 5 | 1066 | Bendere OBOYA |  AUS | 52.37 | 0.172 | 
| 1267 | Amantle MONTSHO |  BOT | DNF | 0.125 | |
| 2234 | Meleni RODNEY |  GRN | DNF | 0.196 | |
| 2660 | Aliya BOSHNAK |  JOR | DQ | 0.238 | 
| POS | BIB | ATHLETE | COUNTRY | MARK | ms* | Reaction Time | 
|---|---|---|---|---|---|---|
| 1 | 3847 | Allyson FELIX |  USA | 50.84 Q | 0.168 | |
| 2 | 2500 | Roneisha MCGREGOR |  JAM | 51.14 Q | .138 | 0.180 | 
| 3 | 1629 | Lada VONDROVÁ |  CZE | 51.14 Q PB | .139 | 0.182 | 
| 4 | 2021 | Ama PIPI |  GBR | 51.17 q | 0.126 | |
| 5 | 1301 | Tiffani MARINHO |  BRA | 52.11 | 0.210 | |
| 6 | 3707 | Leni SHIDA |  UGA | 52.48 | 0.201 | |
| 7 | 1226 | Samantha DIRKS |  BIZ | 54.16 SB | 0.177 | |
| 8 | 3748 | Tetyana MELNYK |  UKR | 54.99 | 0.179 | 
ms - Milliseconds - shown when two or more competitors finish with the same time down to hundredths of a second
| POS | BIB | ATHLETE | COUNTRY | MARK | Reaction Time | 
|---|---|---|---|---|---|
| 1 | 2501 | Candice MCLEOD |  JAM | 51.09 Q | 0.202 | 
| 2 | 1920 | Amandine BROSSIER |  FRA | 51.65 Q | 0.171 | 
| 3 | 1112 | Susanne GOGL-WALLI |  AUT | 52.19 Q | 0.209 | 
| 4 | 2137 | Corinna SCHWAB |  GER | 52.29 | 0.155 | 
| 5 | 2218 | Eirini VASILEIOU |  GRE | 53.16 | 0.164 | 
| 6 | 1268 | Galefele MOROKO |  BOT | 55.89 SB | 0.202 | 
| 2034 | Nicole YEARGIN |  GBR | DQ | 0.182 | |
| 1174 | Cynthia BOLINGO |  BEL | DNS | 
| POS | BIB | ATHLETE | COUNTRY | MARK | Reaction Time | 
|---|---|---|---|---|---|
| 1 | 2502 | Stephenie Ann MCPHERSON |  JAM | 50.89 Q | 0.138 | 
| 2 | 3164 | Natalia KACZMAREK |  POL | 51.06 Q | 0.150 | 
| 3 | 2924 | Paola MORÁN |  MEX | 51.18 Q SB | 0.162 | 
| 4 | 2333 | Phil HEALY |  IRL | 51.98 | 0.158 | 
| 5 | 2757 | Hellen Syombua KALII |  KEN | 52.70 | 0.221 | 
| 6 | 2863 | Agnė ŠERKŠNIENĖ |  LTU | 52.78 | 0.172 | 
| 7 | 1400 | Natassha MCDONALD |  CAN | 53.54 | 0.161 | 
| POS | BIB | ATHLETE | COUNTRY | MARK | Reaction Time | 
|---|---|---|---|---|---|
| 1 | 1684 | Marileidy PAULINO |  DOM | 50.06 Q | 0.184 | 
| 2 | 3857 | Wadeline JONATHAS |  USA | 50.93 Q | 0.209 | 
| 3 | 2995 | Lieke KLAVER |  NED | 51.37 Q | 0.200 | 
| 4 | 1762 | Aauri Lorena BOKESA |  ESP | 51.89 q SB | 0.235 | 
| 5 | 1606 | Eleni ARTYMATA |  CYP | 51.91 q | 0.224 | 
| 6 | 1624 | Barbora MALÍKOVÁ |  CZE | 52.83 | 0.195 | 
| 7 | 1450 | Shalysa WRAY |  CAY | 53.61 | 0.216 | 
| 8 | 1266 | Christine BOTLOGETSWE |  BOT | 53.99 SB | 0.214 |