Allegany County is a county in the U.S. state of New York. As of the 2020 census, the population was 46,456. Its county seat is Belmont. Its name derives from a Lenape word, applied by European-American settlers of Western New York State to a trail that followed the Allegheny River; they also named the county after this. The county is part of the Western New York region of the state.

Belmont is a village within the town of Amity in Allegany County, New York, United States. Belmont is the county seat of Allegany County. The population was 969 at the 2010 census. The name means "beautiful hill". The village is centrally located in Amity and is northeast of Olean.