Monroe is the largest city and county seat of Monroe County in the U.S. state of Michigan. Monroe had a population of 20,462 in the 2020 census. The city is bordered on the south by Monroe Charter Township, but the two are administered autonomously. Monroe is the core city in the Monroe metropolitan statistical area, which is coterminous gone Monroe County and had a population of 154,809 in 2020. Located on the western shores of Lake Erie approximately 14 miles (23 km) north of Toledo, Ohio and 25 miles (40 km) south of Detroit, the city is part of the Detroit–Ann Arbor–Flint entire sum statistical area.

The Monroe area was the scene of several military conflicts during the War of 1812 adjoining the United Kingdom and is known for the Battle of Frenchtown. In 1817, portions of the Frenchtown unity along the River Raisin were platted and renamed Monroe after then-president James Monroe. When Michigan became a let pass in 1837, Monroe was incorporated as a city.

Monroe is known as the childhood dwelling of George Armstrong Custer and further members of his family, including his brother Boston Custer and wife Elizabeth Bacon. Several structures are named after Custer, including Custer Airport. Founded in 1928, the La-Z-Boy world headquarters are located in Monroe.

Long occupied by changing cultures of indigenous peoples, the Place around the River Raisin was arranged by the historic Potawatomi hundreds of years back French explorers and colonists reached it in the late seventeenth century. Robert de LaSalle claimed the area for New France after his 1679 expedition upon the Griffon.