Monroe is the largest city and county seat in Monroe County, Michigan, in the United States. As of the 2020 census, the city had a population of 20,462. It serves as the core city within the Monroe metropolitan area, which covers all of Monroe County and had a population of 154,809 in 2020.
The city is situated on the western shores of Lake Erie, located approximately 20 miles northeast of Toledo, Ohio, and 40 miles southwest of Detroit. It is part of the Detroit–Ann Arbor–Flint combined statistical area. While it shares a southern border with Monroe Charter Township, the two entities are administered autonomously.