Humberside Police were called to the scene on Ferry Road in Scunthorpe at around 4pm on Saturday (Jun 12) following a collision.
The black Kia Sportage was travelling towards Henderson Road when the incident happened.
A spokesman for the force said: "The pedestrian, a three-year-old boy, suffered serious injuries and was taken to hospital via ambulance. His injuries are not believed to be life-threatening.
"The driver of the Kia remained at the scene and is assisting officers in their enquiries."
Officers investigating the crash is asking for anyone who saw the incident or may have dashcam footage to contact them on 101, quoting log number 444 of June 12.
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