Sudbury is a town in Middlesex County, Massachusetts, United States. As of the 2010 census, it had a population of 17,659. The town was incorporated in 1639. At that time, the boundaries Sudbury included (by 1653) all what is now of Wayland (which split off in 1780), and parts of Framingham, Marlborough, Stow and Maynard. The Sudbury Center Historic District has changed little since 1800.