NSW toddler hit by car fighting for life

A toddler has been critically injured when hit by a car in Sydney's west.

Police were called to Fairfield Hospital after the seriously injured two-year-old boy was taken there for treatment.

An investigation is under way with police now speaking with the driver, who is known to the child.

It's believed the boy was hit by the car at Fairfield Heights, and he is being transferred to the Children's Hospital at Westmead.