Oconomowoc is a city in Waukesha County, Wisconsin, United States. The population was 18,203 at the 2020 census. The city is next to the Village of Lac La Belle and near the village of Oconomowoc Lake

Waukesha County is a county in the U.S. state of Wisconsin. As of the 2020 United States Census, the population was 406,978, making it the third-most populous county in Wisconsin. Its median income of