As of the 2000 census, there were 18,567 people comprising 7,225 households, including 4,833 families residing in Southbury. The population density was 475.4 people per square mile (183.5/km). There were 7,799 housing units at an average density of 199.7 per square mile (77.1/km). The racial makeup of the town was 97.34% White, 0.45% African American, 0.08% Native American, 1.15% Asian, 0.01% Pacific Islander, 0.35% from other races, and 0.62% from multiple races. Hispanic or Latino of any race were 1.59% of the population.