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

The Boy'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.

Records
Prior to the competition, the following records were as follows.

During the competition, Egor Kuznetsov lowered the world youth leading to 50.97.

Heats
Qualification rule: first 3 of each heat (Q) plus the 6 fastest times (q) qualified.

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