Williamsville is a village in Erie County, New York, United States. The population was 5,300 at the 2010 census. The village is named after Jonas Williams, an early settler. It is part of the Buffalo–Niagara Falls Metropolitan Statistical 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.
Williamsville is also a postal ZIP code: 14221; however, that ZIP code contains large sections of the town outside the village and also includes significant commercial areas within Clarence.
The Williamsville Central School District is a school system covering Williamsville, most of the eastern part of Amherst, and a small portion of the western end of Clarence.