| POS | Rank | Heat | BIB | ATHLETE | COUNTRY | RESULTS |
|---|---|---|---|---|---|---|
| 1 | 1 | 2 | GBR | Great Britain & NI U20 |
GBR |
41.60 Q WU20R |
| 2 | 1 | 1 | AUS | Australia U20 |
AUS |
41.64 Q WU20R |
| 3 | 2 | 1 | ITA | Italy U20 |
ITA |
41.74 Q PB |
| 4 | 1 | 3 | USA | United States U20 |
USA |
41.82 Q |
| 5 | 2 | 3 | NGR | Nigeria U20 |
NGR |
41.91 Q PB |
| 6 | 3 | 1 | JAM | Jamaica U20 |
JAM |
42.08 Q PB |
| 7 | 3 | 3 | GER | Germany U20 |
GER |
42.12 Q PB |
| 8 | 2 | 2 | FRA | France U20 |
FRA |
42.16 Q PB |
| 9 | 3 | 2 | POL | Poland U20 |
POL |
42.18 Q PB |
| 10 | 4 | 1 | NED | Netherlands U20 |
NED |
42.33 PB |
| 11 | 4 | 3 | SVK | Slovak Republic U20 |
SVK |
42.54 PB |
| 12 | 4 | 2 | ESP | Spain U20 |
ESP |
42.69 PB |
| 13 | 5 | 1 | BRA | Brazil U20 |
BRA |
42.77 PB |
| 14 | 5 | 2 | RSA | South Africa U20 |
RSA |
42.87 PB |
| 15 | 5 | 3 | BEL | Belgium U20 |
BEL |
43.04 |
| 16 | 6 | 3 | CHI | Chile U20 |
CHI |
43.14 PB |
| 17 | 7 | 3 | PER | Peru U20 |
PER |
43.50 PB |
| 18 | 6 | 1 | EST | Estonia U20 |
EST |
43.69 |
| 19 | 7 | 1 | BUL | Bulgaria U20 |
BUL |
43.73 |
| 20 | 6 | 2 | MEX | Mexico U20 |
MEX |
44.67 |
| 21 | 7 | 2 | PNG | Papua New Guinea U20 |
PNG |
45.80 |