| POS | Rank | Heat | BIB | ATHLETE | COUNTRY | RESULTS | ms* |
|---|---|---|---|---|---|---|---|
| 1 | 1 | 5 | 1288 | Emmanuel Kipkurui Korir |
 KEN |
1:45.16 Q | |
| 2 | 2 | 5 | 1379 | Mostafa Smaili |
 MAR |
1:45.27 Q | |
| 3 | 3 | 5 | 1591 | Wesley Vázquez |
 PUR |
1:45.47 Q | |
| 4 | 1 | 6 | 828 | Elliot Giles |
 GBR |
1:45.53 Q | |
| 5 | 2 | 6 | 1919 | Clayton Murphy |
 USA |
1:45.62 Q | .611 |
| 6 | 3 | 6 | 272 | Amel Tuka |
 BIH |
1:45.62 Q | .616 |
| 7 | 4 | 6 | 651 | Álvaro De Arriba |
 ESP |
1:45.67 q | .666 |
| 7 | 4 | 5 | 104 | Yassine Hethat |
 ALG |
1:45.67 | .666 |
| 9 | 1 | 3 | 412 | Brandon McBride |
 CAN |
1:45.96 Q | |
| 10 | 1 | 4 | 1295 | Ferguson Cheruiyot Rotich |
KEN |
1:45.98 Q | |
| 11 | 2 | 4 | 1896 | Bryce Hoppel |
USA |
1:46.01 Q | |
| 12 | 1 | 1 | 1871 | Donavan Brazier |
USA |
1:46.04 Q | |
| 13 | 1 | 2 | 1281 | Ngeno Kipngetich |
KEN |
1:46.07 Q | |
| 14 | 3 | 4 | 1765 | Abdessalem Ayouni |
 TUN |
1:46.09 Q | |
| 15 | 2 | 3 | 1593 | Abubaker Haydar Abdalla |
 QAT |
1:46.11 Q | |
| 16 | 2 | 1 | 395 | Marco Arop |
CAN |
1:46.12 Q | .113 |
| 17 | 2 | 2 | 647 | Adrián Ben |
ESP |
1:46.12 Q | .117 |
| 18 | 5 | 5 | 845 | Kyle Langford |
GBR |
1:46.14 | .138 |
| 18 | 3 | 3 | 761 | Pierre-Ambroise Bosse |
 FRA |
1:46.14 Q | .138 |
| 20 | 4 | 4 | 1376 | Oussama Nabil |
MAR |
1:46.17 q | |
| 21 | 5 | 4 | 1531 | Adam Kszczot |
 POL |
1:46.20 q | |
| 22 | 3 | 2 | 851 | Jamie Webb |
GBR |
1:46.23 Q | |
| 23 | 4 | 2 | 1905 | Brannon Kidder |
USA |
1:46.29 q | |
| 24 | 5 | 2 | 2083 | Jamal Hairane |
QAT |
1:46.40 | |
| 25 | 6 | 4 | 103 | Mohamed Belbachir |
ALG |
1:46.52 | |
| 26 | 3 | 1 | 1645 | Tshepo Tshite |
 RSA |
1:46.54 Q | |
| 27 | 4 | 3 | 1381 | Mouad Zahafi |
MAR |
1:46.56 | |
| 28 | 4 | 1 | 1711 | Andreas Kramer |
 SWE |
1:46.74 | |
| 29 | 5 | 6 | 1588 | Andrés Arroyo |
PUR |
1:46.75 | |
| 30 | 5 | 1 | 2029 | Lucirio Garrido |
 VEN |
1:46.89 | |
| 31 | 5 | 3 | 159 | Peter Bol |
 AUS |
1:46.92 | |
| 32 | 7 | 4 | 2074 | Mark English |
 IRL |
1:47.25 | |
| 33 | 6 | 2 | 927 | Marc Reuther |
 GER |
1:47.31 | |
| 34 | 6 | 6 | 1456 | Edose Ibadin |
 NGR |
1:47.91 | |
| 35 | 7 | 6 | 1333 | Musa Hajdari |
 KOS |
1:47.98 | |
| 36 | 6 | 5 | 1013 | Quamel Prince |
 GUY |
1:48.41 | |
| 37 | 6 | 3 | 138 | Pol Moya |
 AND |
1:48.52 | |
| 38 | 6 | 1 | 656 | Mariano García |
ESP |
1:49.08 | |
| 39 | 7 | 1 | 168 | Luke Mathews |
AUS |
1:50.16 | |
| 40 | 7 | 5 | 1511 | Mohammed Al-Suleimani |
 OMA |
1:50.91 PB | |
| 41 | 8 | 5 | 899 | Benjamín Enzema |
 GEQ |
1:51.69 SB | |
| 42 | 7 | 3 | 1590 | Ryan Sánchez |
PUR |
1:54.46 | |
| 43 | 8 | 1 | 1418 | Min Min Zaw |
 MYA |
1:56.85 SB | |
| 44 | 8 | 3 | 1742 | Roberto Belo Amaral Soares |
 TLS |
2:02.43 | |
| 6 | 1207 | Samer Ali Saleh Al Johar |
 JOR |
DQ | |||
| 2 | 303 | Nijel Amos |
 BOT |
DNS |
Legend
ms - Milliseconds - shown when two or more competitors finish with the same time down to hundredths of a second