Brookfield is a city located in Waukesha County, Wisconsin, United States in the Milwaukee metropolitan area. It had a population of 37,920 in the 2010 census. Brookfield is the third largest city in Waukesha County. The city is adjacent to the Town of Brookfield.

Delafield is a city in Waukesha County, Wisconsin, along the Bark River. The population was 7,085 at the 2010 census. The city of Delafield is a separate municipality from the Town of Delafield, both of which are situated in township 7 North Range 18 East.

Milwaukee (, locally ) is the largest city in the U.S. state of Wisconsin and the fifth-largest city in the Midwestern United States. The seat of Milwaukee County, the city is located on Lake Michigan's southwestern shore and was incorporated in 1846. As of the 2020 census, Milwaukee had a population of 577,222, a decrease from 594,833 in 2010. It is the 31st largest city in the United States and the fourth-largest city situated along one of the Great Lakes. It is the main cultural and economic center of the Milwaukee metropolitan area, the fourth-most densely populated metropolitan area in the Midwest. Milwaukee is considered a "Gamma −" global city as categorized by the Globalization and World Cities Research Network with a regional GDP of over $107 billion.Today, Milwaukee is one of the most ethnically and culturally diverse cities in the United States. Its history was heavily influenced by German immigrants in the 19th century and it became well known for its brewing industry. In recent years, Milwaukee has been undergoing its largest construction boom since the 1960s. Major new additions to the city in the past two decades include the Milwaukee Riverwalk, the Wisconsin Center, American Family Field, The Hop (streetcar system), an expansion to the Milwaukee Art Museum, Milwaukee Repertory Theater, the Bradley Symphony Center, and Discovery World, as well as major renovations to the UW–Milwaukee Panther Arena. Fiserv Forum opened in late 2018 and hosts sporting events and concerts. Since 1968, Milwaukee has been home to Summerfest, one of the largest music festivals in the world. With regard to education, Milwaukee is home to UW-Milwaukee, Marquette University, MSOE, and several other universities and colleges. The city is home to two major professional sports teams, the Bucks and Brewers. It is home to several Fortune 500 companies, including Northwestern Mutual, WEC Energy Group, Rockwell Automation, and Harley-Davidson.

Jefferson County is a county in the U.S. state of Wisconsin. As of the 2010 census, the population was 83,686. Its county seat is Jefferson. Jefferson County comprises the Watertown-Fort Atkinson, WI Micropolitan Statistical Area, which is also included in the Milwaukee-Racine-Waukesha, WI Combined Statistical Area.