Andover is a town in Essex County, Massachusetts, United States. It was settled in 1642 and incorporated in 1646. At the 2020 census, the population was 36,569. It is located 20 miles (32 km) north of Boston and 4 miles (6.4 km) south of Lawrence. Part of the town comprises the census-designated place of Andover. It is twinned with its namesake: Andover, Hampshire, England.