Pozycja | Bieg | Tor | Zawodnik | Państwo | Czas | Uwagi |
1 | 5 | 6 | Makwala, IsaacIsaac Makwala | Botswana | 44,55 | Q |
2 | 4 | 7 | Gardiner, StevenSteven Gardiner | Bahamy | 44,75 | Q |
3 | 3 | 6 | Thebe, BabolokiBaboloki Thebe | Botswana | 44,82 | Q |
4 | 6 | 6 | Allen, NathonNathon Allen | Jamajka | 44,91 | Q |
5 | 1 | 7 | Kerley, FredFred Kerley | Stany Zjednoczone | 44,92 | Q |
6 | 6 | 3 | Roberts, GilGil Roberts | Stany Zjednoczone | 44,92 | Q |
7 | 3 | 8 | Gaye, DemishDemish Gaye | Jamajka | 44,92 | Q |
8 | 5 | 9 | Merritt, LaShawnLaShawn Merritt | Stany Zjednoczone | 45,00 | Q |
9 | 1 | 8 | Gordon, LalondeLalonde Gordon | Trynidad i Tobago | 45,02 | Q,  |
10 | 5 | 2 | Walton, JamalJamal Walton | Kajmany | 45,05 | Q |
11 | 1 | 6 | Borlée, KévinKévin Borlée | Belgia | 45,09 | Q |
12 | 1 | 9 | Maslák, PavelPavel Maslák | Czechy | 45,10 | q,  |
13 | 4 | 5 | London, WilWil London | Stany Zjednoczone | 45,10 | Q |
14 | 5 | 5 | Husillos, ÓscarÓscar Husillos | Hiszpania | 45,22 | q,  |
15 | 6 | 9 | Harun, Abd al-IlahAbd al-Ilah Harun | Katar | 45,27 | Q |
16 | 2 | 5 | van Niekerk, WaydeWayde van Niekerk | Południowa Afryka | 45,27 | Q |
17 | 1 | 5 | Hudson-Smith, MatthewMatthew Hudson-Smith | Wielka Brytania | 45,31 | q |
18 | 4 | 4 | Gregan, BrianBrian Gregan | Irlandia | 45,37 | Q |
19 | 3 | 3 | Cowan, DwayneDwayne Cowan | Wielka Brytania | 45,39 | Q |
20 | 3 | 7 | Mweresa, BonifaceBoniface Mweresa | Kenia | 45,58 | q |
21 | 3 | 9 | Omelko, RafałRafał Omelko | Polska | 45,69 | q |
22 | 4 | 9 | Borlée, JonathanJonathan Borlée | Belgia | 45,70 | q |
23 | 2 | 2 | Re, DavideDavide Re | Włochy | 45,71 | Q |
24 | 4 | 8 | Santos, LuguelínLuguelín Santos | Dominikana | 45,73 | |
25 | 5 | 3 | Kibet, RaymondRaymond Kibet | Kenia | 45,75 | |
26 | 5 | 8 | Rooney, MartynMartyn Rooney | Wielka Brytania | 45,75 | |
27 | 2 | 3 | Cedenio, MachelMachel Cedenio | Trynidad i Tobago | 45,77 | Q |
28 | 1 | 4 | Carvalho, LucasLucas Carvalho | Brazylia | 45,86 | |
29 | 4 | 3 | Hanne, MamoudouMamoudou Hanne | Francja | 45,89 | |
30 | 2 | 4 | Atine-Venel, TeddyTeddy Atine-Venel | Francja | 45,90 | |
31 | 2 | 6 | Lescay, YoandysYoandys Lescay | Kuba | 45,93 | |
32 | 5 | 7 | Quow, RennyRenny Quow | Trynidad i Tobago | 45,95 | |
33 | 6 | 4 | Anas, MohammadMohammad Anas | Indie | 45,98 | |
34 | 1 | 3 | Búa, LucasLucas Búa | Hiszpania | 46,00 | |
35 | 5 | 1 | George, WinstonWinston George | Gujana | 46,02 | |
36 | 2 | 1 | Janežič, LukaLuka Janežič | Słowenia | 46,06 | |
37 | 1 | 2 | Omae Gichana, CollinsCollins Omae Gichana | Kenia | 46,10 | |
38 | 2 | 9 | Solomon, StevenSteven Solomon | Australia | 46,27 | |
39 | 3 | 4 | García, SamuelSamuel García | Hiszpania | 46,37 | |
40 | 3 | 2 | Conradie, PieterPieter Conradie | Południowa Afryka | 46,62 | |
41 | 6 | 5 | Oghenewegba Nathaniel, SamsonSamson Oghenewegba Nathaniel | Nigeria | 46,63 | |
42 | 3 | 1 | Hazel, WarrenWarren Hazel | Saint Kitts i Nevis | 46,96 | |
43 | 2 | 7 | Shearman, KimorieKimorie Shearman | Saint Vincent i Grenadyny | 47,05 | |
44 | 4 | 2 | Herrera, YilmarYilmar Herrera | Kolumbia | 47,18 | |
45 | 6 | 8 | Kitagawa, TakamasaTakamasa Kitagawa | Japonia | 47,35 | |
46 | 6 | 7 | Sibanda, KaraboKarabo Sibanda | Botswana | 47,44 | |
47 | 1 | 1 | Mahamat, BachirBachir Mahamat | Czad | 47,50 | |
48 | 5 | 4 | Tubuilagi, SailosiSailosi Tubuilagi | Fidżi | 48,98 | |
49 | 3 | 5 | Ghukasyan, NarekNarek Ghukasyan | Armenia | 49,70 |  |
50 !- | 2 | 8 | Brenes, NeryNery Brenes | Kostaryka | 99,99DQ !DQ | R 163,3(a) |
50 !- | 4 | 6 | Gayle, StevenSteven Gayle | Jamajka | 99,99DQ !DQ | R 163,3(a) |
52 !- | 6 | 2 | Dasor, EmmanuelEmmanuel Dasor | Ghana | 99,99DNS !DNS | |