The 18-month-old boy was left injured by the roadside after being struck by a white car in Chatburn Road, near the Preston Road roundabout, at around 12.39pm.
The youngster was taken to Royal Preston Hospital with a broken ankle, but has since been discharged and is continuing his recovery at home.
Police are seeking to identify the driver of the car, which is believed to be a Peugeot, that had reportedly left the scene before officers arrived.
A police spokesman said: "We are appealing for the driver of a car involved in a collision which left an 18-month-old boy with a broken ankle to come forward.
"Officers were contacted by the ambulance service at 12.39pm on Friday (December 11) to reports of a collision in Chatburn Road, Longridge, involving the child and a white vehicle.
"The car, which is possibly a Peugeot, initially stopped at the scene for a short time but left before police arrived.
"The boy was taken to Royal Preston Hospital by ambulance but has since been discharged."
PC Mike Smith, of Lancashire Police’s Tactical Operations, added: "A little boy has been left with a serious injury and at this stage we are trying to establish what happened.
"We really need to speak to the driver of this white vehicle and I would appeal directly to that person to make contact with police as soon as possible.
"I would also ask for anybody with information or dash cam or CCTV footage of the incident to come forward."
Anyone with information is asked to email [email protected] or call 101, quoting log 0604 or December 11, 2020.
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