The shooting happened about 4:30 Friday afternoon near 69th and Bishop.
The 15-year-old boy was reportedly shot in the leg and is in good condition at Comer Children's Hospital.
The victim's brother said the boy, a Harper High School student, was walking with a group of kids in the Englewood neighborhood when the shot was fired at the group.
Police are looking for the gunman and investigating a motive. But relatives of the teen say he was not in a gang.