The incident occurred around 12.20pm on Fishponds Lane in the Chapelthorpe area of Wakefield when the 6-year-old pedestrian was struck by what is thought to have been a grey or light coloured small hatchback type vehicle which failed to stop at the scene.
Detective Chief Inspector Simon Bottomley, from the Force’s Homicide and Major Enquiry Team, said: “This is a tragic incident which has devastated the boy’s family.
“At this stage we believe the driver was a young white male and the vehicle is likely to have front end damage as a result of the collision.
“I would urge anyone with information to come forward and contact the police.”
Anyone with information is asked to contact the Major Collision Enquiry Team via: 0845 60 60 606.
The identity of the boy is not expected to be released today.