Firefighters from Whitby, Danby, Lythe and Loftus attended, along with the Great North Air Ambulance which airlifted the child to James Cook University Hospital in Middlesbrough.
As the Whitby Gazette went to press yesterday he was in a stable condition in hospital.
The crash happened at just before 3.45pm.
The boy's mother (36), who was driving a silver Volkswagen Beetle when it hit a grey Skoda Octavia, was taken to the same hospital after suffering a broken arm and head injuries.
It happened at the entrance to the Safari Garage
None of the injuries sustained by mother or son are believed to be life-threatening.
The road was re-opened at 6.38pm, just over three hours after the accident.
Police officers are particularly interested in speaking with the occupants of a dark blue car which is believed to have been travelling between the Skoda and VW just prior to the collision and may have vital information about the manner of driving of the vehicles.
Anyone who witnessed the collision, or saw the manner of driving of any of the vehicle prior to the incident, is asked to contact Traffic Constable Bryan Wilson of the force's Roads Policing Group, on 0845 60 60 24 7, quoting reference number 12100124042.