The crash, on Dewsbury Road, Beeston, happened at about 8.10 am today (Tuesday).
A black Audi A3 Sport car collided with the boy, 11, a spokesman for West Yorkshire Police said.
The boy was taken to hospital with a leg injury that has been described as "serious".
The car stopped at the scene.
The force has appealed for any witnesses to the collision to come forward.
Anyone with information is asked to call police on 101.