Potosi is a town in Grant County, Wisconsin, United States. The population was 831 at the 2000 census. The Village of Potosi is located within the town. The unincorporated communities of British Hollow, Buena Vista, Rockville, and Van Buren are located in the town.
According to the United States Census Bureau, the town has a total area of 57.7 square miles (149.4 km²), of which, 46.5 square miles (120.3 km²) of it is land and 11.2 square miles (29.1 km²) of it (19.45%) is water.
As of the census of 2000, there were 831 people, 299 households, and 232 families residing in the town. The population density was 17.9 people per square mile (6.9/km²). There were 337 housing units at an average density of 7.3 per square mile (2.8/km²). The racial makeup of the town was 99.40% White, and 0.60% from two or more races. 0.00% of the population were Hispanic or Latino of any race.
There were 299 households out of which 36.1% had children under the age of 18 living with them, 67.9% were married couples living together, 5.0% had a female householder with no husband present, and 22.4% were non-families. 17.4% of all households were made up of individuals and 4.3% had someone living alone who was 65 years of age or older. The average household size was 2.78 and the average family size was 3.16.
In the town, the population was spread out with 28.5% under the age of 18, 7.0% from 18 to 24, 28.9% from 25 to 44, 26.6% from 45 to 64, and 9.0% who were 65 years of age or older. The median age was 37 years. For every 100 females there were 114.2 males. For every 100 females age 18 and over, there were 116.0 males.
The median income for a household in the town was $42,697, and the median income for a family was $44,141. Males had a median income of $28,056 versus $18,929 for females. The per capita income for the town was $16,379. About 1.7% of families and 3.9% of the population were below the poverty line, including 5.9% of those under age 18 and 1.4% of those age 65 or over.