Belgium is a town in Ozaukee County, Wisconsin, United States. The population was 1,513 at the 2000 census. The Village of Belgium is located within the town. The unincorporated communities of Decker, Holy Cross, Lake Church, and Sauk Trail Beach are located in the town. The unincorporated community of Dacada is located partially in the town.
According to the United States Census Bureau, the town has a total area of 36.8 square miles (95.3 km²), of which, 35.7 square miles (92.6 km²) of it is land and 1.1 square miles (2.7 km²) of it (2.88%) is water.
As of the census of 2009, there were 2,008 people, 547 households, and 421 families residing in the town. The population density was 42.3 people per square mile (16.3/km²). There were 631 housing units at an average density of 17.7 per square mile (6.8/km²). The racial makeup of the town was 98.02% White, 0.07% Native American, 0.53% Asian, 0.40% from other races, and 0.99% from two or more races. 1.06% of the population were Hispanic or Latino of any race.
There were 547 households out of which 33.1% had children under the age of 18 living with them, 66.7% were married couples living together, 6.0% had a female householder with no husband present, and 22.9% were non-families. 18.3% of all households were made up of individuals and 6.4% had someone living alone who was 65 years of age or older. The average household size was 2.77 and the average family size was 3.19.
In the town, the population was spread out with 27.0% under the age of 18, 6.4% from 18 to 24, 28.5% from 25 to 44, 25.0% from 45 to 64, and 13.2% who were 65 years of age or older. The median age was 39 years. For every 100 females, there were 109.0 males. For every 100 females age 18 and over, there were 110.1 males.
The median income for a household in the town was $57,865, and the median income for a family was $62,500. Males had a median income of $42,083 versus $26,875 for females. The per capita income for the town was $24,746. About 1.6% of families and 2.2% of the population were below the poverty line, including 0.5% of those under age 18 and 2.3% of those age 65 or over.