The Cook County Medical Examiner's Office said Amaria Osby was found unresponsive in a home in the 4600-block of North Winthrop Avenue about 11 a.m. She was pronounced dead at the scene.
A woman, approximately 38, was also found in the home and taken to Weiss Hospital. Police said she is in good condition.
RELATED: 'Fear in their eyes': Texas investigators describe conditions in which 8-year-old's remains found
The relationship between the woman and the child was not immediately known.
An investigation by Chicago police is ongoing.