Berlin is a town in Worcester County, Massachusetts, United States. The town was first settled in 1665 and incorporated in 1812, and is governed under the open town meeting system. It is located 12 miles (19 km) northeast of Worcester and 29 miles (47 km) west of Boston. The population was 3,158 at the 2020 census.

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.