Wellsville is a town and largest community in Allegany County, New York, United States. As of the 2020 census, the town had a population of 7,099. Wellsville is centrally located in the south half of the county, 8 miles north of the Pennsylvania border. Wellsville is also the name of the main village within this town. The village and the town have two separate, paid go…Wellsville is a town and largest community in Allegany County, New York, United States. As of the 2020 census, the town had a population of 7,099. Wellsville is centrally located in the south half of the county, 8 miles north of the Pennsylvania border. Wellsville is also the name of the main village within this town. The village and the town have two separate, paid governments. Alfred State College maintains a branch campus in the town, with the main campus in Alfred 7 miles east.