Pewaukee is a city in Waukesha County, Wisconsin. The population was 15,914 at the 2020 census. The Village of Pewaukee, which was incorporated out of the town before it incorporated as a city, is surrounded by the city. The name of the city of Pewaukee comes from that of the name of the village, which is rather unclear in itself. Many names have been given as to the etymology of the name.