Northbridge is a town in Worcester County, Massachusetts, United States. The population was 16,335 at the 2020 census. The Northbridge Town Hall is located at 7 Main Street in Whitinsville. The town is now a part of the Blackstone River Valley National Heritage Corridor, of the National Park Service. Northbridge claims to history include: Native American Nipmuc lands, Colonel John Spring, who led the Uxbridge militia training company in the American Revolution, Samuel Spring, Revolutionary War Chaplain, the Residence of Ezra T. Benson 1830–1832, the birthplace of President Millard Fillmore's mother, Phoebe, and home to the Whitin Machine Works from 1831 to 1964.

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.