The boy was riding on Brantingham Road, Elloughton, when he was hit from behind and knocked down by a car at about 23:15 BST on Friday.
The driver failed to stop and the boy was found lying injured in the road, Humberside Police said.
Sgt Claire Hall said: "At this stage we have little detail about the vehicle involved.
"However we do believe it will have sustained some damage, possibly some dents or some smashed glass.
"I am appealing to the driver of the vehicle to come forward, or anyone who has information about the collision or the vehicle or driver involved."
A 16-year-old cyclist is in hospital with life-threatening injuries after a hit-and-run in East Yorkshire