Milwaukee is the most populous city in the U.S. state of Wisconsin and the seat of Milwaukee County. Located on the western shore of Lake Mic…Milwaukee is the most populous city in the U.S. state of Wisconsin and the seat of Milwaukee County. Located on the western shore of Lake Michigan, it is the 31st-most populous city in the United States and the fifth-most populous city in the Midwest with a population of 577,222 at the 2020 census. The Milwaukee metropolitan area is the 40th-most populous metro area in the U.S. with 1.57 million residents.