Detroit, Illinois is a village in Pike County, Illinois, United States. The population was 83 at the 2010 census, a decline from 93 in 2000.

Pike County is a county in the U.S. state of Illinois. It is located between the Mississippi River and the Illinois River in western Illinois. According to the 2020 United States Census, it had a population of 14,739. Its county seat is Pittsfield.