Hampden County is a non-governmental county located in the Pioneer Valley of the state of Massachusetts, in the United States. As of the 2020 census, Hampden County's population was 465,825. Its traditional county seat is Springfield, the Connecticut River Valley's largest city, and economic and cultural capital; with an estimated population of 154,758, approximately 1 in 3 residents of Hampden County live in Springfield. Hampden County was split from Hampshire County in 1812, because Northampton, Massachusetts, was made Hampshire County's "shire town" in 1794; however, Springfield—theretofore Hampshire County's traditional shire town, dating back to its founding in 1636—grew at a pace far quicker than Northampton and was granted shire town-status over its own, southerly jurisdiction. It was named for parliamentarian John Hampden. To the north of Hampden County is modern-day Hampshire County; to the west is Berkshire County; to the east is Worcester County; to the south are Litchfield County, Hartford County, and Tolland County in Connecticut. Hampden County is part of the Springfield, MA Metropolitan Statistical Area. It is the most urban county in Western Massachusetts. The Knowledge Corridor surrounding Springfield-Hartford is New England's second most populous urban area (after Greater Boston) with 1.9 million people. Law and government As with most Massachusetts counties, Hampden County exists today only as a historical geographic region, and has no county government. All former county functions were assumed by state agencies in 1998. The sheriff and some other regional officials with specific duties are still elected locally to perform duties within the county region, but there is no county council, county commission or other county governing body. Communities are now granted the right to form their own regional compacts for sharing services. Hampden County and Hampshire County together are part of the Pioneer Valley Planning Commission. Government and politics |} Geography According to the U.S. Census Bureau, the county has a total area of , of which is land and (2.7%) is water. Adjacent counties Hampshire County (north) Worcester County (east) Tolland County, Connecticut (southeast) Hartford County, Connecticut (south) Litchfield County, Connecticut (southwest) Berkshire County (west) Communities Cities Agawam Chicopee Holyoke Palmer Springfield (traditional county seat) West Springfield Westfield Towns Blandford Brimfield Chester East Longmeadow Granville Hampden Holland Longmeadow Ludlow Monson Montgomery Russell Southwick Tolland Wales Wilbraham Census-designated places Blandford Chester Holland Monson Center Russell Wilbraham Other unincorporated communities Bondsville Depot Village Feeding Hills Three Rivers Woronoco City neighborhoods The following are