First 2 in each heat (Q) and the next 2 fastest (q)

First 2 of each heat (Q) plus 2 fastest times (q) qualify to Final

POS Rank Heat BIB ATHLETE COUNTRY RESULTS ms*
1 1 3 1207 Natalia KACZMAREK POLPOL 49.50 Q
2 1 1 711 Marileidy PAULINO DOMDOM 49.54 Q
3 2 3 549 Sada WILLIAMS BARBAR 49.58 Q NR
4 2 1 959 Rhasidat ADELEKE IRLIRL 49.87 Q .861
5 1 2 1142 Lieke KLAVER NEDNED 49.87 Q .868
6 3 1 552 Cynthia BOLINGO BELBEL 49.96 q NR
7 4 1 1019 Candice MCLEOD JAMJAM 50.62 q
8 3 3 1411 Lynna IRBY-JACKSON USAUSA 50.71
9 4 3 858 Victoria OHURUOGU GBRGBR 50.74
10 5 3 1255 Andrea MIKLÓS ROUROU 50.77
11 2 2 1390 Talitha DIGGS USAUSA 50.86 Q
12 5 1 661 Evelis AGUILAR COLCOL 51.07 PB .064
13 3 2 676 Roxana GÓMEZ CUBCUB 51.07 .065
14 4 2 861 Ama PIPI GBRGBR 51.17
15 5 2 1023 Nickisha PRYCE JAMJAM 51.24
16 6 3 1040 Charokee YOUNG JAMJAM 51.40
17 6 1 1128 Paola MORÁN MEXMEX 51.46
18 7 3 538 Susanne GOGL-WALLI AUTAUT 51.50 .497
19 7 1 698 Lada VONDROVÁ CZECZE 51.50 .498
20 6 2 1251 Gabby SCOTT PURPUR 51.52
21 8 1 1266 Zenéy GELDENHUYS RSARSA 51.54
22 7 2 965 Sharlene MAWDSLEY IRLIRL 51.78
23 8 3 694 Tereza PETRŽILKOVÁ CZECZE 51.94
24 8 2 1112 Modesta Justė MORAUSKAITĖ LTULTU 52.15
Legend

ms - Milliseconds - shown when two or more competitors finish with the same time down to hundredths of a second