# 2017 World Youth Championships in Athletics – Boys' 400 metres

The Boys' 400 metres at the 2017 World Youth Championships in Athletics was held on 12–14 July.

## Records

Prior to the competition, the following records were as follows.
| World Youth Best | Obea Moore (USA) | 45.14 | Santiago de Chile, Chile | 2 September 1995 |
| Championship Record | Kirani James (GRN) | 45.24 | Bressanone, Italy | 10 July 2009 |
| World Youth Leading | Tyrese Cooper (USA) | 45.38 | Albuquerque, New Mexico, United States | 3 June 2017 |

## Heats

Qualification rule: first 4 of each heat (Q) and the next 4 fastest qualified.
| Heat | Lane | Name | Nationality |
| 1 | 1 | Anthony Cox | Jamaica |
| 1 | 2 | Thiran Kalavitigoda Pathirannahalage | Sri Lanka |
| 1 | 3 | Gregor Grahovac | Slovenia |
| 1 | 4 | Correy Sherrod | Bahamas |
| 1 | 5 | Xu Bo | China |
| 1 | 6 | Patrice Remanoro | Madagascar |
| 1 | 7 | Ali Soleymani | Iran |
| 1 | 8 | Mohammad Jahir Rayhan | Bangladesh |
| 2 | 2 | Daniel Williams | Guyana |
| 2 | 3 | Elvin Josué Canales | Honduras |
| 2 | 4 | Thiruben Thana Rajan | Singapore |
| 2 | 5 | Melkamu Assefa | Ethiopia |
| 2 | 6 | Eric Layeng | Uganda |
| 2 | 7 | José Álvarez | Venezuela |
| 2 | 8 | Antonio Grant | Panama |
| 3 | 1 | Reuben Nichols | Saint Lucia |
| 3 | 2 | Musa Isah | Bahrain |
| 3 | 3 | Manish Manish | India |
| 3 | 4 | Kelvin Sawe Tauta | Kenya |
| 3 | 5 | Elián Larregina | Argentina |
| 3 | 6 | Mohamed Naail | Maldives |
| 3 | 7 | Yaroslav Demchenko | Ukraine |
| 3 | 8 | Nsikak Francis Okon | Nigeria |
| 4 | 1 | Yaroslav Holub | Ukraine |
| 4 | 2 | Deng Hantao | China |
| 4 | 3 | Mohammad Reza Dehghani | Iran |
| 4 | 4 | Alexandru Vlad | Romania |
| 4 | 5 | Antonio Watson | Jamaica |
| 4 | 6 | David Sanayek | Kenya |
| 4 | 7 | Ivan Danny Geldenhuis | Namibia |
| 4 | 8 | Akshay Nain | India |
| 5 | 2 | Tyrell Simms | Bahamas |
| 5 | 3 | Emmanuel Goni | Uganda |
| 5 | 4 | Bruno Benedito da Silva | Brazil |
| 5 | 5 | Diego Camacho | Venezuela |
| 5 | 6 | Kennedy Luchembe | Zambia |
| 5 | 7 | Bernard Olesitse | Botswana |
| 5 | 8 | Colby Jennings | Turks and Caicos Islands |

## Semifinals
### Semifinal 1

| Rank | Name | Nationality | Reaction | Time | Notes |
| 1 | Colby Jennings | Turks and Caicos Islands | 0.224 | 47.36 | Q, PB |
| 2 | Melkamu Assefa | Ethiopia | 0.214 | 47.43 | Q |
| 3 | Kelvin Sawe Tauta | Kenya | 0.370 | 47.55 | |
| 4 | Elvin Josué Canales | Honduras | 0.243 | 48.21 | |
| 5 | Thiruben Thana Rajan | Singapore | 0.171 | 48.40 | |
| 6 | Musa Isah | Bahrain | 0.187 | 48.43 | |
| 7 | Xu Bo | China | 0.226 | 48.90 | |
| 8 | Bernard Olesitse | Botswana | 0.161 | 50.54 | |

### Semifinal 2

| Rank | Name | Nationality | Reaction | Time | Notes |
| 1 | Anthony Cox | Jamaica | 0.266 | 46.86 | Q |
| 2 | Ivan Danny Geldenhuys | Namibia | 0.181 | 47.24 | Q, PB |
| 3 | Daniel Williams | Guyana | 0.186 | 47.46 | q |
| 4 | David Sanayek | Kenya | 0.199 | 47.66 | |
| 5 | Mohammad Jahir Rayhan | Bangladesh | 0.198 | 48.22 | |
| 6 | José Álvarez | Venezuela | 0.160 | 48.79 | |
| 7 | Deng Hantao | China | 0.185 | 49.12 | |
| 8 | Tyrell Simms | Bahamas | 0.167 | 49.38 | |

### Semifinal 3

| Rank | Name | Nationality | Reaction | Time | Notes |
| 1 | Bruno Benedito da Silva | Brazil | 0.215 | 46.87 | Q, PB |
| 2 | Antonio Watson | Jamaica | 0.000 | 47.05 | Q, PB |
| 3 | Gregor Grahovac | Slovenia | 0.183 | 47.34 | q, PB |
| 4 | Yaroslav Demchenko | Ukraine | 0.178 | 47.96 | PB |
| 5 | Reuben Nichols | Saint Lucia | 0.215 | 48.01 | PB |
| 6 | Correy Sherrod | Bahamas | 0.211 | 48.56 | |
| 7 | Thiran Kalavitigoda Pathirannahalage | Sri Lanka | 0.188 | 48.89 | |
| – | Antonio Grant | Panama | — | — | DQ |

## Final

| Rank | Name | Nationality | Reaction | Time | Notes |
| | Antonio Watson | Jamaica | 0.174 | 46.59 | PB |
| | Daniel Williams | Guyana | 0.200 | 46.72 | PB |
| | Colby Jennings | Turks and Caicos Islands | 0.213 | 46.77 | PB |
| 4 | Anthony Cox | Jamaica | 0.210 | 46.77 | |
| 5 | Melkamu Assefa | Ethiopia | 0.249 | 47.05 | |
| 6 | Bruno Benedito da Silva | Brazil | 0.231 | 47.15 | |
| 7 | Ivan Danny Geldenhuys | Namibia | 0.192 | 47.17 | PB |
| 8 | Gregor Grahovac | Slovenia | 0.157 | 48.88 | |