Westville is a town in Franklin County, New York, United States. As of the 2010 census, the town had a population of 1,819. Westville is on the north border of the county, northwest of Malone.
The north town line is the international border with Canada (province of Quebec). According to the United States Census Bureau, the town has a total area of 34.8 square miles (90.2 km), of which 0.02 square miles (0.04 km), or 0.04%, is water.
New York State Route 37 intersects New York State Route 122 at Westville Center.
The Salmon River, a tributary of the St. Lawrence River, flows northward through the town.
As of the census of 2000, there were 1,823 people, 671 households, and 503 families residing in the town. The population density was 52.4 people per square mile (20.2/km²). There were 766 housing units at an average density of 22.0 per square mile (8.5/km²). The racial makeup of the town was 96.98% White, 0.66% African American, 0.82% Native American, 0.16% Asian, and 1.37% from two or more races. Hispanic or Latino of any race were 0.82% of the population.
There were 671 households out of which 34.4% had children under the age of 18 living with them, 61.1% were married couples living together, 7.6% had a female householder with no husband present, and 25.0% were non-families. 19.4% of all households were made up of individuals and 8.3% had someone living alone who was 65 years of age or older. The average household size was 2.71 and the average family size was 3.07.
In the town, the population was spread out with 26.9% under the age of 18, 7.7% from 18 to 24, 30.4% from 25 to 44, 24.8% from 45 to 64, and 10.1% who were 65 years of age or older. The median age was 36 years. For every 100 females, there were 101.7 males. For every 100 females age 18 and over, there were 100.8 males.
The median income for a household in the town was $32,452, and the median income for a family was $36,964. Males had a median income of $28,167 versus $20,291 for females. The per capita income for the town was $15,809. About 9.4% of families and 12.8% of the population were below the poverty line, including 15.7% of those under age 18 and 10.5% of those age 65 or over.