Mendon is a town in Worcester County, Massachusetts, United States. The population was 6,228 at the 2020 census. Mendon is part of the Blackstone River Valley National Heritage Corridor, an early center of the industrial revolution in the United States. Mendon celebrated its 350th anniversary on May 15, 2017.

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.