| | Event type
400 metres Hurdles, Boys
| Date | 13 – 16 October 2018 | |
|---|---|---|
| Status | YOG | |
| Location | Athletics Field, Parque Olímpico de la Juventud, Villa Soldati, Buenos Aires | |
| Participants | 16 from 16 countries | |
| Format | Two stages with final results determined by cumulative time. | |
| Pos | Nr | Athlete | NOC | Time | Stage One | Stage Two | |||
|---|---|---|---|---|---|---|---|---|---|
| 1 | – | Haruto Deguchi |  JPN | 1:42.68 | 51.40 (1) | 51.28 (1) | Gold | ||
| 2 | – | Dániel Huller |  HUN | 1:43.84 | 51.98 (3) | 51.86 (2) | Silver | ||
| 3 | – | Mohammed Duhaim Almuawi |  KSA | 1:45.81 | 52.76 (6) | 53.05 (4) | Bronze | ||
| 4 | – | Martin Fraysse |  FRA | 1:45.85 | 53.13 (7) | 52.72 (3) | |||
| 5 | – | Pedro Garrido |  ARG | 1:46.78 | 52.22 (4) | 54.56 (9) | |||
| 6 | – | Shanthamoi Brown |  JAM | 1:47.14 | 53.87 (8) | 53.27 (=5) | |||
| 7 | – | Thomas Throssell |  AUS | 1:47.49 | 54.22 (9) | 53.27 (=5) | |||
| 8 | – | Caio de Almeida |  BRA | 1:47.92 | 52.27 (5) | 55.65 (13) | |||
| 9 | – | Alejandro Gil |  MEX | 1:49.18 | 54.89 (10) | 54.29 (7) | |||
| 10 | – | Chang Chun-Yu |  TPE | 1:49.51 | 55.16 (12) | 54.35 (8) | |||
| 11 | – | Ignacio Sáez |  ESP | 1:50.36 | 55.05 (11) | 55.31 (11) | |||
| 12 | – | Rami Balti |  TUN | 1:50.62 | 56.03 (15) | 54.59 (10) | |||
| 13 | – | Matthew Thompson |  BAH | 1:50.81 | 55.43 (13) | 55.38 (12) | |||
| 14 | – | Mauricio Lizano |  CRC | 1:51.90 | 56.00 (14) | 55.90 (14) | |||
| – | Lindukuhle Gora |  RSA | – | 51.70 (2) | – ( | ||||
| – | Eloi Kiendrebeogo |  BUR | – | – ( | 58.84 (15) |