Detroit is the most populous city in the U.S. state of Michigan. It is the largest U.S. city on the Canadian border and the county seat of Wayne County. Detroit had a population of 639,111 at the 2020 census, making it the 26th-most populous city in the United States. The Metro Detroit area, home to 4.3 million people, is the second-largest in the Midwest after the Chicago metropolitan area and the 14th-largest in the United States.