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.

Final
22 July

Semifinals
21 July

Heats
20 July

Participation
According to an unofficial count, 38 athletes from 28 countries participated in the event. • 🇦🇺 australia (1)

• undefined (2)

• undefined (1)

• 🇧🇾 belarus (1)

• 🇧🇷 brazil (1)

• undefined (2)

• 🇨🇦 canada (2)

• undefined (1)

• 🇪🇨 ecuador (1)

• 🇫🇮 finland (1)

• 🇫🇷 france (1)

• 🇩🇪 germany (2)

• undefined (1)

• 🇮🇶 iraq (1)

• 🇮🇹 italy (1)

• 🇯🇲 jamaica (2)

• 🇯🇵 japan (1)

• 🇲🇰 macedonia (1)

• 🇲🇹 malta (1)

• 🇳🇿 new zealand (1)

• undefined (2)

• 🇷🇴 romania (2)

• 🇷🇺 russia (1)

• undefined (1)

• 🇸🇪 sweden (2)

• undefined (2)

• 🇺🇸 united states (2)

• undefined (1)