Muskego is a city in Waukesha County, Wisconsin, United States. As of the 2000 census, the city had a population of 21,397. Its 2006-2008 estimated population was 22,851. Muskego is the fifth largest community in Waukesha County. The name Muskego is derived from the Potawatomi Indian name for the area, "Mus-kee-Guaac", meaning sunfish. The Potawatomi were the original inhabitants of Muskego. There are three lakes within the city's boundaries.