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 (19 km2) 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.
As of the census of 2000, there were 8,828 people, 3,310 households, and 2,502 families residing in the village. The population density was 1,464.0 people per square mile (565.3/km2). There were 3,441 housing units at an average density of 570.6 per square mile (220.3/km2). The racial makeup of the village was 96.98% White, 0.75% African American, 0.18% Native American, 0.80% Asian, 0.05% Pacific Islander, 0.36% from other races, and 0.88% from two or more races. Hispanic or Latino of any race were 1.67% of the population.
There were 3,310 households out of which 41.9% had children under the age of 18 living with them, 63.1% were married couples living together, 9.5% had a female householder with no husband present, and 24.4% were non-families. 19.5% of all households were made up of individuals and 7.6% had someone living alone who was 65 years of age or older. The average household size was 2.67 and the average family size was 3.09.