| POS | Rank | Heat | BIB | ATHLETE | COUNTRY | RESULTS | ms* | 
|---|---|---|---|---|---|---|---|
| 1 | 1 | 1 | 3295 | Abderrahman Almoubarrake S ALSALECK | 
 QAT                 | 
                48.38 Q | |
| 2 | 2 | 1 | 1318 | Alison DOS SANTOS | 
 BRA                 | 
                48.42 Q | |
| 3 | 1 | 2 | 2592 | Jaheel HYDE | 
 JAM                 | 
                48.54 Q | |
| 4 | 1 | 5 | 3907 | Rai BENJAMIN | 
 USA                 | 
                48.60 Q | |
| 5 | 2 | 2 | 3968 | Kenneth SELMON | 
 USA                 | 
                48.61 Q | |
| 6 | 1 | 3 | 3086 | Karsten WARHOLM | 
 NOR                 | 
                48.65 Q | |
| 7 | 2 | 5 | 1824 | Rasmus MÄGI | 
 EST                 | 
                48.73 Q | |
| 8 | 1 | 4 | 2456 | Kyron MCMASTER | 
 IVB                 | 
                48.79 Q | |
| 9 | 3 | 1 | 1008 | Abdelmalik LAHOULOU | 
 ALG                 | 
                48.83 Q SB | |
| 10 | 2 | 4 | 3668 | Yasmani COPELLO | 
 TUR                 | 
                49.00 Q | |
| 11 | 2 | 3 | 2341 | Thomas BARR | 
 IRL                 | 
                49.02 Q | |
| 12 | 4 | 1 | 2611 | Kemar MOWATT | 
 JAM                 | 
                49.06 Q | |
| 13 | 3 | 3 | 2439 | Alessandro SIBILIO | 
 ITA                 | 
                49.11 Q | |
| 14 | 3 | 4 | 2626 | Shawn ROWE | 
 JAM                 | 
                49.18 Q SB | |
| 15 | 4 | 3 | 2154 | Luke CAMPBELL | 
 GER                 | 
                49.19 Q SB | |
| 16 | 3 | 2 | 2724 | Hiromu YAMAUCHI | 
 JPN                 | 
                49.21 Q | |
| 17 | 4 | 4 | 3939 | David KENDZIERA | 
 USA                 | 
                49.23 Q | .229 | 
| 17 | 5 | 1 | 1979 | Ludvy VAILLANT | 
 FRA                 | 
                49.23 q | .229 | 
| 19 | 5 | 3 | 1958 | Wilfried HAPPIO | 
 FRA                 | 
                49.39 q | |
| 20 | 5 | 4 | 2145 | Joshua ABUAKU | 
 GER                 | 
                49.50 q SB | |
| 21 | 3 | 5 | 3444 | Sokwakhana ZAZINI | 
 RSA                 | 
                49.51 Q SB | |
| 22 | 4 | 5 | 3026 | Nick SMIDT | 
 NED                 | 
                49.55 Q | |
| 23 | 5 | 5 | 1637 | Vít MÜLLER | 
 CZE                 | 
                49.59 q | |
| 24 | 6 | 3 | 1333 | Marcio TELES | 
 BRA                 | 
                49.70 SB | |
| 25 | 4 | 2 | 2172 | Constantin PREIS | 
 GER                 | 
                49.73 Q | |
| 26 | 6 | 1 | 2274 | Máté KOROKNAI | 
 HUN                 | 
                49.80 | |
| 27 | 7 | 3 | 1564 | Gerald DRUMMOND | 
 CRC                 | 
                49.92 | |
| 28 | 6 | 5 | 2683 | Takatoshi ABE | 
 JPN                 | 
                49.98 | |
| 29 | 6 | 4 | 2702 | Kazuki KUROKAWA | 
 JPN                 | 
                50.30 | |
| 30 | 5 | 2 | 2962 | Creve Armando MACHAVA | 
 MOZ                 | 
                50.37 SB | |
| 31 | 6 | 2 | 3649 | Mohamed TOUATI | 
 TUN                 | 
                50.58 | |
| 32 | 7 | 4 | 1562 | Jordin ANDRADE | 
 CPV                 | 
                50.64 SB | |
| 33 | 7 | 5 | 2299 | Jabir MADARI PALLIYALIL | 
 IND                 | 
                50.77 | |
| 34 | 7 | 1 | 3602 | Chieh CHEN | 
 TPE                 | 
                50.96 =SB | |
| 35 | 7 | 2 | 1791 | Sergio FERNÁNDEZ | 
 ESP                 | 
                51.51 | |
| 36 | 8 | 2 | 3457 | Ned AZEMIA | 
 SEY                 | 
                51.67 | 
ms - Milliseconds - shown when two or more competitors finish with the same time down to hundredths of a second