Hampshire County, Massachusetts

Hampshire County, Massachusetts
Location within the U.S. state of Massachusetts
Coordinates: 42°20′N 72°40′W / 42.34°N 72.66°W / 42.34; -72.66
Country United States
State Massachusetts
Founded1662
Named afterHampshire, England
SeatNorthampton
Largest townAmherst
Area
 • Total
545 sq mi (1,410 km2)
 • Land527 sq mi (1,360 km2)
 • Water18 sq mi (47 km2)  3.3%
Population
 (2020)
 • Total
162,308
 • Estimate 
(2024)
165,399
 • Density308/sq mi (119/km2)
Time zoneUTC−5 (Eastern)
 • Summer (DST)UTC−4 (EDT)
Congressional districts1st, 2nd
Websitevisithampshirecounty.com

Hampshire County is a historical and judicial county located in the U.S. state of Massachusetts. As of the 2020 census, the population was 162,308. Its most populous municipality is Amherst (due to seasonal student population; the largest year-round is Northampton, which is also its traditional county seat), and its largest town in terms of landmass is Belchertown. The county is named after the county Hampshire, in England. Hampshire County is part of the Springfield, MA Metropolitan Statistical Area. Together with Hampden County, Hampshire County municipalities belong to the Pioneer Valley Planning Commission.