Maynard is a town in Middlesex County, Massachusetts, United States. The town is located 25 miles west of Boston, in the MetroWest region of Massachusetts. As of the 2010 census, the town population was 10,106. Maynard was the site of the Assabet Woolen Mill, which produced wool fabrics near the Assabet River for over 100 years, from 1846 to 1950, under various owners.