Williamsville is a village in Erie County, New York, United States. The population was 5,423 at the 2020 census. The village is named after Jonas Williams, an early settler. It is part of the Buffalo-Niagara Falls metropolitan area. Williamsville is located mostly within the town of Amherst, but Creek Road and Creek Heights in the south part of the village are in the town of Cheektowaga. The village is in the northeastern quadrant of Erie County.