It happened around 1 p.m. Sunday afternoon on Geneva Avenue near Courier.
The Kane County Sheriff's office said the driver of a black Dodge pickup drove away, abandoned the car a few blocks from the scene and started running.
The child was airlifted to a Chicago area hospital with potential life threatening injuries.
The driver is described as a male white, approximately 5'6, weighing around 120 pounds with a pony tail and wearing tan pants.
Anyone with information is asked to call 911.