Millbury is a town in Worcester County, Massachusetts, United States. The population was 13,261 at the 2010 census.
Millbury was first settled by white Europeans in 1716 and was officially incorporated in 1813.Millbury has a long history as a New England mill town, from which the town's name is derived. The Blackstone River flows through the town which during the Industrial Revolution provided much of the water power to the town's many textile mills and factories.Millbury was originally the Second or North Parish of Sutton. Because traveling from one part of Sutton to the other for town meetings, etc. was difficult and time-consuming, the inhabitants of the Northern Parish petitioned the Massachusetts General Court to split the town of Sutton into two separate towns. The North Parish became the town of Millbury on June 11, 1813 by way of an act of incorporation.