Sussex is a village in Waukesha County, Wisconsin, United States. It is approximately 19 miles (31 km) northwest of Milwaukee and 9 miles (14 km) north of Waukesha. The village is 7.24 square miles at an elevation of 930 feet. The population was 8,828 at the 2000 census, with an estimated population of 10,045 in 2008. It is part of the Milwaukee metropolitan area.