| POS | Rank | Heat | BIB | ATHLETE | COUNTRY | RESULTS | ms* | WIND | 
|---|---|---|---|---|---|---|---|---|
| 1 | 1 | 3 | 1425 | Andre DE GRASSE |  CAN | 19.73 Q NR | +0.2 | |
| 2 | 2 | 3 | 3905 | Kenneth BEDNAREK |  USA | 19.83 Q | +0.2 | |
| 3 | 1 | 2 | 1423 | Aaron BROWN |  CAN | 19.99 Q SB | .982 | -0.4 | 
| 4 | 2 | 2 | 2848 | Joseph FAHNBULLEH |  LBR | 19.99 Q NR | .982 | -0.4 | 
| 5 | 3 | 2 | 3950 | Noah LYLES |  USA | 19.99 q | .983 | -0.4 | 
| 6 | 1 | 1 | 3944 | Erriyon KNIGHTON |  USA | 20.02 Q | -0.2 | |
| 7 | 3 | 3 | 3634 | Jereem RICHARDS |  TTO | 20.10 q SB | +0.2 | |
| 8 | 2 | 1 | 2572 | Rasheed DWYER |  JAM | 20.13 Q SB | -0.2 | |
| 9 | 3 | 1 | 3060 | Divine ODUDURU |  NGR | 20.16 | -0.2 | |
| 10 | 4 | 3 | 3418 | Shaun MASWANGANYI |  RSA | 20.18 | +0.2 | |
| 11 | 5 | 3 | 3580 | Sibusiso MATSENJWA |  SWZ | 20.22 NR | +0.2 | |
| 12 | 4 | 2 | 1686 | Yancarlos MARTÍNEZ |  DOM | 20.24 | -0.4 | |
| 13 | 4 | 1 | 2196 | Joseph Paul AMOAH |  GHA | 20.27 SB | -0.2 | |
| 14 | 6 | 3 | 3670 | Ramil GULIYEV |  TUR | 20.31 SB | +0.2 | |
| 15 | 5 | 1 | 3294 | Femi OGUNODE |  QAT | 20.34 | -0.2 | |
| 16 | 6 | 1 | 2419 | Eseosa Fostine DESALU |  ITA | 20.43 | -0.2 | |
| 17 | 5 | 2 | 3524 | William REAIS |  SUI | 20.44 SB | -0.4 | |
| 18 | 7 | 1 | 1508 | Zhenye XIE |  CHN | 20.45 | -0.2 | |
| 19 | 6 | 2 | 3426 | Clarence MUNYAI |  RSA | 20.49 =SB | -0.4 | |
| 20 | 7 | 3 | 2349 | Leon REID |  IRL | 20.54 | +0.2 | |
| 21 | 8 | 1 | 3408 | Anaso JOBODWANA |  RSA | 20.88 | -0.2 | |
| 22 | 8 | 3 | 3016 | Taymir BURNET |  NED | 20.90 | +0.2 | |
| 23 | 7 | 2 | 1203 | Robin VANDERBEMDEN |  BEL | 21.00 | -0.4 | |
| 2 | 3125 | Alonso EDWARD |  PAN | DNF | 
ms - Milliseconds - shown when two or more competitors finish with the same time down to hundredths of a second