# 2010 World Junior Championships in Athletics – Women's 400 metres

The women's 400 metres event at the 2010 World Junior Championships in Athletics was held in Moncton, New Brunswick, Canada, at Moncton Stadium on 20, 21 and 22 July.

## Medalists

| Gold | Shaunae Miller Bahamas |
| Silver | Margaret Etim Nigeria |
| Bronze | Bianca Răzor Romania |

## Results
### Final

22 July
| Rank | Name | Nationality | Time |
| | Shaunae Miller | Bahamas | 52.52 |
| | Margaret Etim | Nigeria | 53.05 |
| | Bianca Răzor | Romania | 53.17 |
| 4 | Stacey-Ann Smith | United States | 53.42 |
| 5 | Jody-Ann Muir | Jamaica | 53.42 |
| 6 | Bukola Abogunloko | Nigeria | 53.74 |
| 7 | Regina George | United States | 53.83 |
| 8 | Chantel Malone | British Virgin Islands | 53.91 |

### Semifinals

21 July

#### Semifinal 1

| Rank | Name | Nationality | Time | Notes |
| 1 | Bukola Abogunloko | Nigeria | 52.86 | Q |
| 2 | Bianca Răzor | Romania | 53.06 | Q |
| 3 | Jody-Ann Muir | Jamaica | 53.20 | q |
| 4 | Regina George | United States | 53.59 | q |
| 5 | Anneliese Rubie | Australia | 54.39 | |
| 6 | Gulustan Mahmood | Iraq | 54.70 | |
| 7 | Christina Zwirner | Germany | 54.86 | |
| 8 | Miho Shingu | Japan | 55.66 | |

#### Semifinal 2

| Rank | Name | Nationality | Time | Notes |
| 1 | Margaret Etim | Nigeria | 52.63 | Q |
| 2 | Shaunae Miller | Bahamas | 53.21 | Q |
| 3 | Bárbara de Oliveira | Brazil | 53.60 | |
| 4 | Ella Räsänen | Finland | 53.73 | |
| 5 | Katherine Reid | Canada | 53.80 | |
| 6 | Sade Sealy | Barbados | 54.90 | |
| 7 | Julia Schaefers | Germany | 55.09 | |
| | Yuliya Yurenia | Belarus | DQ | IAAF rule 162.7 |

#### Semifinal 3

| Rank | Name | Nationality | Time | Notes |
| 1 | Chantel Malone | British Virgin Islands | 53.37 | Q |
| 2 | Stacey-Ann Smith | United States | 53.48 | Q |
| 3 | Chanice Chase | Canada | 53.72 | |
| 4 | Maria Lebedeva | Russia | 53.86 | |
| 5 | Rashan Brown | Bahamas | 54.14 | |
| 6 | Adelina Pastor | Romania | 54.47 | |
| 7 | Janieve Russell | Jamaica | 55.16 | |
| 8 | Marta Maffioletti | Italy | 55.72 | |

### Heats

20 July

#### Heat 1

| Rank | Name | Nationality | Time | Notes |
| 1 | Maria Lebedeva | Russia | 54.02 | Q |
| 2 | Regina George | United States | 54.17 | Q |
| 3 | Janieve Russell | Jamaica | 54.65 | Q |
| 4 | Yuliya Yurenia | Belarus | 54.67 | Q |
| 5 | Rashan Brown | Bahamas | 54.85 | q |
| 6 | Sandra Wagner | Sweden | 55.28 | |
| 7 | Shawna Fermin | Trinidad and Tobago | 55.50 | |
| 8 | Romana Tea Kirinic | Croatia | 56.27 | |

#### Heat 2

| Rank | Name | Nationality | Time | Notes |
| 1 | Bukola Abogunloko | Nigeria | 53.38 | Q |
| 2 | Stacey-Ann Smith | United States | 53.41 | Q |
| 3 | Chanice Chase | Canada | 53.61 | Q |
| 4 | Adelina Pastor | Romania | 53.74 | Q |
| 5 | Christina Zwirner | Germany | 54.57 | q |
| 6 | Deseree King | U.S. Virgin Islands | 56.73 | |
| 7 | Hristina Risteska | North Macedonia | 58.80 | |
| 8 | Kristie Baillie | New Zealand | 59.98 | |

#### Heat 3

| Rank | Name | Nationality | Time | Notes |
| 1 | Shaunae Miller | Bahamas | 52.45 | Q |
| 2 | Margaret Etim | Nigeria | 52.48 | Q |
| 3 | Ella Räsänen | Finland | 53.87 | Q |
| 4 | Anneliese Rubie | Australia | 54.29 | Q |
| 5 | Miho Shingu | Japan | 54.79 | q |
| 6 | Liona Rebernik | Slovenia | 55.60 | |
| 7 | Ashley Kelly | British Virgin Islands | 55.71 | |

#### Heat 4

| Rank | Name | Nationality | Time | Notes |
| 1 | Chantel Malone | British Virgin Islands | 52.97 | Q |
| 2 | Bárbara de Oliveira | Brazil | 53.35 | Q |
| 3 | Katherine Reid | Canada | 54.48 | Q |
| 4 | Marta Maffioletti | Italy | 54.98 | Q |
| 5 | Sparkle McKnight | Trinidad and Tobago | 55.01 | |
| 6 | Liliana Núñez | Ecuador | 56.30 | |
| 7 | Kanika Beckles | Grenada | 58.95 | |

#### Heat 5

| Rank | Name | Nationality | Time | Notes |
| 1 | Jody-Ann Muir | Jamaica | 53.83 | Q |
| 2 | Bianca Răzor | Romania | 53.85 | Q |
| 3 | Gulustan Mahmood | Iraq | 54.62 | Q |
| 4 | Julia Schaefers | Germany | 54.65 | Q |
| 5 | Sade Sealy | Barbados | 54.88 | q |
| 6 | Elin Moraiti | Sweden | 55.95 | |
| 7 | Malama Dosso | France | 56.40 | |
| 8 | Francesca Xuereb | Malta | 56.61 | |

## Participation

According to an unofficial count, 38 athletes from 28 countries participated in the event.
* Australia (1)
* Bahamas (2)
* Barbados (1)
* Belarus (1)
* Brazil (1)
* British Virgin Islands (2)
* Canada (2)
* Croatia (1)
* Ecuador (1)
* Finland (1)
* France (1)
* Germany (2)
* Grenada (1)
* Iraq (1)
* Italy (1)
* Jamaica (2)
* Japan (1)
* North Macedonia (1)
* Malta (1)
* New Zealand (1)
* Nigeria (2)
* Romania (2)
* Russia (1)
* Slovenia (1)
* Sweden (2)
* Trinidad and Tobago (2)
* United States (2)
* U.S. Virgin Islands (1)