2011 World Youth Championships in Athletics – Girls' 400 metres hurdles

The women's 400 metres hurdles at the 2011 World Youth Championships in Athletics was held at the Stadium Nord Lille Métropole on 6, 7 and 9 July.

Heats
Qualification rule: first 4 of each heat (Q) plus the 4 fastest times (q) qualified.

Semifinals
Qualification rule: first 2 of each heat (Q) plus the 2 fastest times (q) qualified.