Semifinal 1
dimanche 6 août 2017, 20h40 GMT – 20h40 GMT
| Nom | Équipe | Temps | |
|---|---|---|---|
| 1 |  Steven Gardiner | Bahamas | 43.89″ |
| 2 |  Nathon Allen | Jamaica | + 0.3″ |
| 3 |  Fred Kerley | United States | + 0.62″ |
| 4 |  Kevin Borlée | Belgium | + 1.21″ |
| 5 |  Wilbert London | United States | + 1.23″ |
| 6 |  Oscar Husillos | Spain | + 1.27″ |
| 7 |  Rafal Omelko | Poland | + 1.48″ |
| 8 | Dwayne Cowan | Great Britain | + 2.07″ |