Unadilla is a town in Otsego County, New York, United States. As of the 2010 census, the town had a population of 4,392. The name is derived from an Iroquois word for "meeting place". Unadilla is located in the southwest corner of the county, southwest of Oneonta. The Village of Unadilla is located in the southern part of the town. The mayor of Unadilla is David Welch, as of January 13, 2020.
The first settlement occurred around 1770 in the area of Sidney (in adjacent Delaware County), followed by Unadilla. Both Sidney and Unadilla were destroyed during the American Revolution and were re-established after the war. The town was formed from part of the Town of Otsego in 1792. Later the size of the town was reduced by the formation of new towns: Butternuts, Milford, and Oneonta in 1796, Otego (town), New York in 1822, and an addition to Butternuts in 1857.