Greenfield is the county seat, and sole city, of Franklin County, Massachusetts, United States. Greenfield was first settled in 1686. The population was 17,768 at the 2020 census. Greenfield is home to Greenfield Community College, the Pioneer Valley Symphony Orchestra, the Franklin County Fair, and the Green River Festival. The city has a Main Street Historic District containing fine examples of Federal, Greek Revival, and Victorian architecture.

Greenfield anchors the Greenfield Town, MA Micropolitan Statistical Area, which is included in the Springfield-Greenfield Town, MA Combined Statistical Area.