First 3 in each heat (Q) and the next 6 fastest (q)

First 3 of each heat (Q) plus 6 fastest times (q) qualify to Semi-Final

POS Rank Heat BIB ATHLETE COUNTRY RESULTS ms*
1 1 5 1595 Bayapo NDORI BOTBOT 44.87 Q PB
2 1 1 2268 Wayde VAN NIEKERK RSARSA 45.18 Q
3 2 5 1945 Kirani JAMES GRNGRN 45.29 Q
4 1 2 2410 Michael NORMAN USAUSA 45.37 Q
5 2 1 1566 Jonathan JONES BARBAR 45.46 Q
6 1 6 1874 Matthew HUDSON-SMITH GBRGBR 45.49 Q
7 1 4 2351 Champion ALLISON USAUSA 45.56 Q
8 3 5 2014 Nathon ALLEN JAMJAM 45.61 Q
9 3 1 1872 Alex HAYDOCK-WILSON GBRGBR 45.62 Q SB
10 2 2 2041 Christopher TAYLOR JAMJAM 45.68 Q
11 3 2 2264 Zakithi NENE RSARSA 45.69 Q
12 2 4 1571 Dylan BORLÉE BELBEL 45.70 Q
13 4 2 1572 Kévin BORLÉE BELBEL 45.72 q
14 1 3 2366 Michael CHERRY USAUSA 45.81 Q
15 2 3 2437 Muzala SAMUKONGA ZAMZAM 45.82 Q .811
16 2 6 2159 Liemarvin BONEVACIA NEDNED 45.82 Q .815
17 3 6 1736 Lidio Andres FELIZ DOMDOM 45.87 Q
18 4 5 2069 Fuga SATO JPNJPN 45.88 q
19 4 1 2075 Julian Jrummi WALSH JPNJPN 45.90 q
20 3 4 1594 Isaac MAKWALA BOTBOT 45.93 Q
21 5 5 1526 Alex BECK AUSAUS 45.99 q
22 4 4 2080 Mikhail LITVIN KAZKAZ 46.00 q SB
23 4 6 1979 Christopher O'DONNELL IRLIRL 46.01 q
24 5 1 1719 Patrik Å ORM CZECZE 46.07
25 3 3 1579 Alexander DOOM BELBEL 46.18 Q
26 5 2 1731 Benjamin Lobo VEDEL DENDEN 46.27
27 5 6 2057 Kaito KAWABATA JPNJPN 46.34
28 4 3 2035 Jevaughn POWELL JAMJAM 46.42
29 6 5 2009 Edoardo SCOTTI ITAITA 46.46
30 6 2 2141 Luis AVILÉS FERREIRO MEXMEX 46.47
31 5 4 2008 Davide RE ITAITA 46.49
32 7 2 2220 Kajetan DUSZYŃSKI POLPOL 46.57
33 6 4 2321 Dwight ST. HILLAIRE TTOTTO 46.60 .596
34 5 3 2293 Ricky PETRUCCIANI SUISUI 46.60 .598
35 7 4 2282 Boško KIJANOVIĆ SRBSRB 46.85
36 6 1 1551 Steven SOLOMON AUSAUS 46.87
37 6 3 1597 Anthony PESELA BOTBOT 47.36
38 6 6 1605 Lucas CARVALHO BRABRA 47.53
39 7 5 2154 Dexter MAYORGA NCANCA 48.40
40 7 6 1502 Aiden HAZZARD AIAAIA 51.44 SB
41 7 3 2436 Obediah TIMBACI VANVAN 53.32
Legend

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