Забеги
- Дата: 14 сентября
- Q: 1-3 места в каждом забеге
- q: 6 спортсменов показавших лучшие результаты
Забег 1
| Place | Lane | Athlete | Nation | Time | Notes |
| 1 | 7 | Jereem Richards | Trinidad and Tobago | 44.64 | Q |
| 2 | 4 | Lythe Pillay | South Africa | 44.73 | Q, SB |
| 3 | 5 | Charlie Dobson | Great Britain & N.I. | 44.85 | Q |
| 4 | 8 | Daniel Segers | Belgium | 45.04 | |
| 5 | 2 | Fuga Sato | Japan | 45.10 | SB |
| 6 | 6 | Brian Tinega | Kenya | 45.13 | |
| 7 | 9 | Oleksandr Pohorilko | Ukraine | 45.44 | |
| 8 | 3 | Maksymilian Szwed | Poland | 45.67 |
Забег 2
| Place | Lane | Athlete | Nation | Time | Notes |
| 1 | 5 | Bayapo Ndori | Botswana | 44.36 | Q |
| 2 | 4 | Yuki Joseph Nakajima | Japan | 44.44 | Q, NR |
| 3 | 9 | Bovel McPherson | Jamaica | 44.51 | Q, PB |
| 4 | 6 | Matthew Hudson-Smith | Great Britain & N.I. | 44.68 | q |
| 5 | 8 | Elián Larregina | Argentina | 44.97 | |
| 6 | 7 | Alexander Doom | Belgium | 45.10 | |
| 7 | 3 | Cooper Sherman | Australia | 45.53 | |
| 8 | 2 | Chidi Okezie | Nigeria | 45.66 |
Забег 3
| Place | Lane | Athlete | Nation | Time | Notes |
| 1 | 8 | Jacory Patterson | United States | 43.90 | Q |
| 2 | 4 | Rusheen McDonald | Jamaica | 44.38 | Q, SB |
| 3 | 9 | Edoardo Scotti | Italy | 44.45 | Q, NR |
| 4 | 6 | Collen Kebinatshipi | Botswana | 44.48 | q, SB |
| 5 | 5 | Samuel Ogazi | Nigeria | 45.97 | |
| 6 | 2 | Jean Paul Bredau | Germany | 46.05 | |
| 7 | 7 | Jonas Phijffers | Netherlands | 46.26 | |
| 8 | 3 | Umar Osman | Malaysia | 46.43 |
Забег 4
| Place | Lane | Athlete | Nation | Time | Notes |
| 1 | 7 | Christopher Bailey | United States | 44.49 | Q |
| 2 | 5 | Reece Holder | Australia | 44.54 | Q, =SB |
| 3 | 6 | Muzala Samukonga | Zambia | 44.56 | Q |
| 4 | 8 | Samuel Reardon | Great Britain & N.I. | 44.70 | q |
| 5 | 9 | Patrik Simon Enyingi | Hungary | 45.25 | |
| 6 | 4 | Kevin Kipkorir | Kenya | 45.39 | |
| 7 | 2 | Lionel Spitz | Switzerland | 45.57 | |
| 8 | 3 | Eugene Omalla | Netherlands | 45.97 |
Забег 5
| Place | Lane | Athlete | Nation | Time | Notes |
| 1 | 7 | Zakithi Nene | South Africa | 44.34 | Q |
| 2 | 5 | Vernon Norwood | United States | 44.55 [.544] | Q |
| 3 | 8 | Attila Molnár | Hungary | 44.55 [.548] | Q, NR |
| 4 | 2 | Ammar Ibrahim | Qatar | 44.63 | q, PB |
| 5 | 6 | Rok Ferlan | Slovenia | 44.91 | q |
| 6 | 9 | Mihai Dringo | Romania | 45.21 | |
| 7 | 3 | Luca Sito | Italy | 46.22 | |
| 8 | 4 | Antonio Watson | Jamaica | 46.23 |
Забег 6
| Place | Lane | Athlete | Nation | Time | Notes |
| 1 | 8 | Khaleb McRae | United States | 44.25 | Q |
| 2 | 6 | Lee Eppie | Botswana | 44.44 | Q |
| 3 | 5 | Kirani James | Grenada | 44.66 | Q |
| 4 | 3 | Delano Kennedy | Jamaica | 44.74 | q, PB |
| 5 | 7 | George Mutinda | Kenya | 45.07 | |
| 6 | 9 | Christopher Morales Williams | Canada | 45.26 | |
| 7 | 4 | Alexander Ogando | Dominican Republic | 45.59 | |
| 8 | 2 | Isaya Klein Ikkink | Netherlands | 46.32 |
Полуфиналы
- Дата: 16 сентября
- Q: 1-2 места в каждом забеге
- q: 2 спортсмена, показавших лучшие результаты
Полуфинал 1
| Place | Lane | Athlete | Nation | Time | Notes |
| 1 | 7 | Zakithi Nene | South Africa | 44.20 | Q |
| 2 | 6 | Lee Eppie | Botswana | 44.51 | Q |
| 3 | 8 | Reece Holder | Australia | 44.63 | |
| 4 | 2 | Ammar Ibrahim | Qatar | 44.74 | |
| 5 | 4 | Attila Molnár | Hungary | 44.94 | |
| 6 | 9 | Bovel McPherson | Jamaica | 44.99 | |
| 7 | 5 | Christopher Bailey | United States | 45.05 | |
| 8 | 3 | Samuel Reardon | Great Britain & N.I. | 45.10 |
Полуфинал 2
| Place | Lane | Athlete | Nation | Time | Notes |
| 1 | 3 | Collen Kebinatshipi | Botswana | 43.61 | Q, NR, WL |
| 2 | 7 | Rusheen McDonald | Jamaica | 44.04 | Q, SB |
| 3 | 6 | Jereem Richards | Trinidad and Tobago | 44.12 | q, SB |
| 4 | 5 | Jacory Patterson | United States | 44.19 | q |
| 5 | 9 | Edoardo Scotti | Italy | 44.77 | |
| 6 | 8 | Lythe Pillay | South Africa | 44.82 | |
| 7 | 4 | Charlie Dobson | Great Britain & N.I. | 44.85 | |
| 8 | 2 | Rok Ferlan | Slovenia | 45.71 |
Полуфинал 3
| Place | Lane | Athlete | Nation | Time | Notes |
| 1 | 5 | Bayapo Ndori | Botswana | 44.21 | Q, SB |
| 2 | 7 | Yuki Joseph Nakajima | Japan | 44.53 | Q |
| 3 | 9 | Muzala Samukonga | Zambia | 44.60 | |
| 4 | 6 | Khaleb McRae | United States | 44.82 | |
| 5 | 8 | Vernon Norwood | United States | 44.83 | |
| 6 | 2 | Matthew Hudson-Smith | Great Britain & N.I. | 44.95 | |
| 7 | 3 | Delano Kennedy | Jamaica | 44.97 [.970] | |
| 4 | Kirani James | Grenada |
Финал
- Дата: 18 сентября
| Place | Lane | Athlete | Nation | Time | Notes |
| 1 | 5 | Collen Kebinatshipi | Botswana | 43.53 | NR, WL |
| 2 | 2 | Jereem Richards | Trinidad and Tobago | 43.72 | NR |
| 3 | 8 | Bayapo Ndori | Botswana | 44.20 | SB |
| 4 | 6 | Rusheen McDonald | Jamaica | 44.28 | |
| 5 | 7 | Zakithi Nene | South Africa | 44.55 | |
| 6 | 9 | Yuki Joseph Nakajima | Japan | 44.62 | |
| 7 | 3 | Jacory Patterson | United States | 44.70 | |
| 8 | 4 | Lee Eppie | Botswana | 44.77 |
