The man, 26 years old, was found unresponsive on Friday at the former Wadsworth Elementary School building in the city's Woodlawn neighborhood, officials said. He was pronounced dead on the scene.
Alderperson Jeanette Taylor said she was told the man was a migrant. The cause of the man's death is not yet clear, and his name has not yet been released.
In February, the former school building was turned into temporary housing for migrants arriving in Chicago.
Police did not immediately provide further information about the incident.
This is a developing story. Check back with ABC7 for updates.