Erie Township is a civil township of Monroe County in the U.S. state of Michigan. The population was 4,299 at the 2020 census. Sharing a southern border with the city of Toledo, Ohio, about 45 miles (72 km) southwest of the city of Detroit, the township is one of the southernmost areas included in the Detroit–Warren–Ann Arbor Combined Statistical Area.

Monroe County is a county in the U.S. state of Michigan. As of the 2020 Census, the population was 154,809. The largest city and county seat is Monroe. The county was established as the second county in the Michigan Territory in 1817 and was named for then-President James Monroe. Monroe County is coterminous with the Monroe metropolitan statistical area.