Scio is a town in Allegany County, New York, United States. The population was 1,914 at the 2000 census. The town is in the southern half of the county and north of the Village of Wellsville.
The town was first settled around 1805 by Joseph Knight, a minuteman in the American Revolution, from Oneida County. Knights Creek, which flows into the Genesee River near Scio is named for him. The Town of Scio was created in 1823 from the Town of Angelica. Some of its territory was later lost during the formation of the Towns of Amity (1830), Wellsville (1855), and Willing (1851).
According to the United States Census Bureau, the town has a total area of 35.3 square miles (91.3 km²), of which, 35.2 square miles (91.3 km²) of it is land and 0.04 square miles (0.1 km²) of it (0.09%) is water.