Chicago Fire Department officials said the child was in critical condition. Two other victims were also in critical condition, officials said.
Officer Amina Greer said at least 10 ambulances responded to the scene, transporting victims to several area hospitals.
A witness, Julian Harris, told the Chicago Sun-Times that dreadlocked men fired at him from a gray sedan before turning toward Cornell Square Park and firing at people in the area.
He said his 3-year-old nephew was wounded in the cheek.
More From This Section
Authorities said no one had been taken into custody in connection with the shooting.
Francis John, 70, said she was in her apartment when the shooting occurred. She said went down to see what was going on and "a lot of youngsters were running scared." She said she was surprised by what had happened, saying she has lived in the neighbourhood for 30 years.