CPD and the Chicago Fire Department responded to the fire in the Logan Square neighborhood near North Bernard and West Altgeld streets just after 1:30 a.m.
CFD extinguished the fire and found an unresponsive woman inside the house, police said.
The victim was taken to Stroger Hospital, where she was pronounced dead.
The Cook County Medical Examiner's Office identified the victim as 84-year-old Judith Harris
No one else was injured, and no displacements were reported.
CFD is investigating. Authorities did not immediately provide further information.