A witness told police they heard a loud noise and saw a person on the ground early Monday in the East Side neighborhood.
The victim, a male teen believed to be between 17 and 18 years old, was found on the ground unresponsive with a gunshot wound to his head in the 10600 block of South Avenue M just before 3 a.m., Chicago police said.
He was taken to the University of Chicago Medical Center where he was pronounced dead hours later, police said.
A witness told officers they heard a loud noise and saw the teen on the ground, officials said.
No one was in custody.
Area 2 detectives are investigating.