Semifinal 3
dimanche 6 août 2017, 20h40 GMT – 20h40 GMT
| Nom | Équipe | Temps | |
|---|---|---|---|
| 1 |  Isaac Makwala | Botswana | 44.3″ |
| 2 |  Demish Gaye | Jamaica | + 0.25″ |
| 3 |  Gil Roberts | United States | + 0.54″ |
| 4 | Jamal Walton | Cayman Islands | + 0.86″ |
| 5 |  Jonathan Borlee | Belgium | + 0.93″ |
| 6 |  Pavel Maslak | Czech Republic | + 0.94″ |
| 7 | Machel Cedenio | Trinidad & Tobago | + 1.61″ |
| 8 |  Davide Re | Italy | + 1.65″ |