Beaver Dam is a city in Dodge County, Wisconsin, United States, along Beaver Dam Lake and the Beaver Dam River. The population was 16,708 at the 2020 census, making it the largest city primarily located in Dodge County. It is the principal city of the Beaver Dam Micropolitan Statistical area which is included in the larger Milwaukee–Waukesha–Racine CSA. The city is adjacent to the Town of Beaver Dam.