Oconomowoc /oʊˈkɑːnəməˌwɑːk/ is a city in Waukesha County, Wisconsin, United States. The name was derived from Coo-no-mo-wauk, the Potawatomi term for "waterfall." The population was 15,712 at the 2010 census. The city is partially adjacent to the Town of Oconomowoc and near the village of Oconomowoc Lake, Wisconsin.