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.

The Buffalo–Niagara Falls Metropolitan Statistical Area is a metropolitan area, designated by the United States Census Bureau, encompassing two counties - Erie and Niagara - in the state of New York. It has a population of over 1.1 million people and is the second-largest metropolitan area in the state. As of the 2020 U S. census, the metropolitan statistical area (MSA) had a population of 1,166,902. The larger Buffalo Niagara Region is an economic zone consisting of eight counties in Western New York.