| POS | Rank | Heat | BIB | ATHLETE | COUNTRY | RESULTS | ms* | 
|---|---|---|---|---|---|---|---|
| 1 | 1 | 1 | 133 | Julien WATRIN | 
 BEL                 | 
                45.88 Q NIR | |
| 2 | 1 | 5 | 421 | Carl BENGTSTRÖM | 
 SWE                 | 
                46.45 Q | |
| 3 | 2 | 1 | 444 | Trevor BASSITT | 
 USA                 | 
                46.47 Q | |
| 4 | 2 | 5 | 293 | Christopher TAYLOR | 
 JAM                 | 
                46.48 Q | |
| 5 | 3 | 5 | 187 | Bruno HORTELANO-ROIG | 
 ESP                 | 
                46.49 q | .483 | 
| 6 | 1 | 3 | 171 | Patrik ŠORM | 
 CZE                 | 
                46.49 Q | .485 | 
| 7 | 2 | 3 | 175 | Benjamin Lobo VEDEL | 
 DEN                 | 
                46.58 Q | |
| 8 | 1 | 4 | 469 | Marqueze WASHINGTON | 
 USA                 | 
                46.66 Q | |
| 9 | 1 | 2 | 437 | Jereem RICHARDS | 
 TTO                 | 
                46.69 Q | |
| 10 | 2 | 2 | 299 | Mikhail LITVIN | 
 KAZ                 | 
                46.72 Q | |
| 11 | 3 | 1 | 363 | Kajetan DUSZYŃSKI | 
 POL                 | 
                46.75 q | |
| 12 | 3 | 3 | 240 | Patrick SCHNEIDER | 
 GER                 | 
                46.76 | |
| 13 | 4 | 3 | 113 | Tom WILLEMS | 
 AUS                 | 
                46.77 | |
| 14 | 2 | 4 | 402 | Boško KIJANOVIĆ | 
 SRB                 | 
                46.88 Q | |
| 15 | 3 | 2 | 391 | Zakithi NENE | 
 RSA                 | 
                46.92 | |
| 16 | 4 | 5 | 348 | Håvard Bentdal INGVALDSEN | 
 NOR                 | 
                46.95 | |
| 17 | 4 | 1 | 332 | Isayah BOERS | 
 NED                 | 
                47.07 | |
| 18 | 3 | 4 | 167 | Pavel MASLÁK | 
 CZE                 | 
                47.31 | |
| 19 | 5 | 1 | 309 | Mazen Mawtan AL YASEN | 
 KSA                 | 
                47.65 | |
| 20 | 4 | 2 | 186 | Manuel GUIJARRO | 
 ESP                 | 
                47.74 | |
| 21 | 4 | 4 | 327 | Jovan STOJOSKI | 
 MKD                 | 
                47.80 | |
| 22 | 5 | 2 | 102 | Pau BLASI | 
 AND                 | 
                49.82 | |
| 23 | 5 | 3 | 161 | Quentin PETIT | 
 COM                 | 
                51.55 SB | |
| 24 | 5 | 5 | 275 | Malique SMITH | 
 ISV                 | 
                51.98 SB | |
| 4 | 142 | Lucas CARVALHO | 
 BRA                 | 
                DQ | 
ms - Milliseconds - shown when two or more competitors finish with the same time down to hundredths of a second