Westborough is a town in Worcester County, Massachusetts, United States. The population was 21,567 at the 2020 Census, in over 7,000 households. Incorporated in 1717, the town is governed under the New England open town meeting system, headed by a five-member elected Board of Selectmen whose duties include licensing, appointing various administrative positions, and calling a town meeting of citizens annually or whenever the need arises.

Worcester County is a county in the U.S. state of Massachusetts. At the 2020 census, the population was 862,111, making it the second-most populous county in Massachusetts. It is also the largest county in Massachusetts by geographic area. The largest city and traditional shire town is Worcester. Worcester County is part of the Worcester, MA–CT metropolitan statistical area and the Boston-Worcester-Providence combined statistical area.