Officers responded to a call about an apartment fire in the Washington Park neighborhood's 5300-block of South Calumet Avenue just after 5 a.m.
Chicago Fire Department firefighters extinguished the fire, police said.
First responders found an unresponsive woman, who was pronounced dead on the scene.
No other injuries were reported.
Detectives are conducting a death investigation, and autopsy results are pending.
What caused the fire was not immediately clear.