Monson is a town in Hampden County, Massachusetts, United States. The population was 8,150 at the 2020 census. It is part of the Springfield, Massachusetts Metropolitan Statistical Area.

Hampden County is a non-governmental county located in the Pioneer Valley of the U.S. 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 one-third of Hampden County residents live in Springfield.