The girl was hit on Parkdale Avenue North and Roxborough around 5:15 p.m., Hamilton rescuers said.
According to Hamilton police, he was walking on Parkdale Avenue with a group of friends when he was hit by a 2005 Nissan Quest at the intersection.
The driver of the vehicle did not stop after the collision and fled the area, police said.
The girl was rushed to an injury center in a life-threatening condition, rescuers said.
Police said Sunday morning that a 30-year-old Hamilton woman was charged with failing to cause bodily harm in connection with the incident.
The police did not name her.
Investigators are asking anyone with more information to contact the police or Crime Stoppers.