The boy was sitting in the front passenger seat when a person in a silver sedan fired shots into the car in the 10600-block of South Ewing Avenue at about 1:50 a.m., police said.
The victim was driven to Advocate Trinity Hospital in the car that has bullet holes in it. Police set up a crime scene around the car in the parking lot of the hospital near the emergency entrance so they could investigate.
The victim was wounded in the shoulder and is in serious condition, police said.
No one is in custody, police said.