Wellsville is the largest community in Allegany County, New York, United States. As of the 2010 census, the town had a population of 7,397.
According to the United States Census Bureau, the town has a total area of 36.7 square miles (95.0 km), of which 36.6 square miles (94.9 km) is land and 0.04 square miles (0.1 km), or 0.10%, is water.
The Genesee River flows northward through the town.
New York State Route 417 intersects New York State Route 19 at Wellsville village, and NY 19 intersects New York State Route 248 by the south town line in Stannards.
As of the census of 2000, there were 7,678 people, 3,192 households, and 1,924 families residing in the town. The population density was 209.4 people per square mile (80.9/km²). There were 3,606 housing units at an average density of 98.4 per square mile (38.0/km²). The racial makeup of the town was 96.65% White, 0.53% Black or African American, 0.26% Native American, 1.24% Asian, 0.00% Pacific Islander, 0.21% from other races, and 1.11% from two or more races. 0.72% of the population were Hispanic or Latino of any race.
There were 3,192 households out of which 26.9% had children under the age of 18 living with them, 46.9% were married couples living together, 9.9% had a female householder with no husband present, and 39.7% were non-families. 33.6% of all households were made up of individuals and 15.2% had someone living alone who was 65 years of age or older. The average household size was 2.29 and the average family size was 2.92.
In the town, the population was spread out with 22.9% under the age of 18, 7.5% from 18 to 24, 25.2% from 25 to 44, 23.7% from 45 to 64, and 20.7% who were 65 years of age or older. The median age was 41 years. For every 100 females, there were 90.4 males. For every 100 females age 18 and over, there were 86.5 males.
The median income for a household in the town was $30,098, and the median income for a family was $39,705. Males had a median income of $36,302 versus $23,387 for females. The per capita income for the town was $18,744. 16.0% of the population and 10.6% of families were below the poverty line. 17.9% of those under the age of 18 and 9.2% of those 65 and older were living below the poverty line.