Dewsbury Road was closed for around three hours following the accident at around 7.48am this morning (Monday).
West Yorkshire Police said a Skoda car and a pedestrian were involved in the accident.
The child suffered serious, but not life-threatening injuries and was taken by ambulance to Leeds General Infirmary.
Buses were diverted as Dewsbury Road was closed towards the White Rose Shopping Centre.
Bus operator First said the 2,3, 12 and 13 services were among those affected.
Police could not confirm the age or sex of the injured youngster.