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

POS Rank Heat BIB ATHLETE COUNTRY RESULTS ms*
1 1 2 222 Steven Gardiner BAHBAH 44.13 Q SB
2 2 2 1001 Kirani James GRNGRN 44.23 Q SB
3 1 1 1903 Fred Kerley USAUSA 44.25 Q
4 2 1 1288 Emmanuel Kipkurui Korir KENKEN 44.37 Q SB
5 1 3 1749 Machel Cedenio TTOTTO 44.41 Q SB
6 2 3 536 Anthony José Zambrano COLCOL 44.55 Q NR
7 3 2 1158 ​Demish Gaye JAMJAM 44.66 q SB
8 3 3 1154 Akeem Bloomfield JAMJAM 44.77 q
9 3 1 1096 Davide Re ITAITA 44.85
10 4 2 1921 Vernon Norwood USAUSA 45.00 .992
11 5 2 305 Leungo Scotch BOTBOT 45.00 PB .996
12 4 1 244 Jonathan Sacoor BELBEL 45.03 PB
13 4 3 1217 Julian Jrummi Walsh JPNJPN 45.13 PB
14 5 3 830 Rabah Yousif GBRGBR 45.15 SB
15 6 2 535 Jhon Alejandro Perlaza COLCOL 45.17
16 5 1 1637 Thapelo Phora RSARSA 45.24
17 6 1 360 Abbas Abubakar Abbas BRNBRN 45.26
18 7 1 1931 Nathan Strother USAUSA 45.34
19 7 2 414 Philip Osei CANCAN 45.44
20 8 2 154 Steven Solomon AUSAUS 45.54 SB
21 6 3 1286 Alphas Leken Kishoyian KENKEN 45.55
22 7 3 1920 Michael Norman USAUSA 45.94
23 8 1 1336 Mazen Moutan Al Yassin KSAKSA 46.11
3 1338 Yousef Karam KUWKUW DNF
Legend

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