Deerfield is a town in Franklin County, Massachusetts, United States. The population was 5,125 as of the 2010 census. Deerfield is part of the Springfield, Massachusetts Metropolitan Statistical Area in western Massachusetts, lying 30 miles north of the city of Springfield.Deerfield includes the villages of South Deerfield and Old Deerfield which is home to two museums; Pocumtuck Valley Memorial Association and Historic Deerfield, Inc. Historic Deerfield, Inc. is a museum with a focus on decorative arts, early American material culture, and history. Its house museums offer interpretation of society, history, and culture from the colonial era through the late nineteenth century. Pocumtuck Valley Memorial Association has Memorial Hall Museum which opened in 1880, as well as the Indian House Memorial Children's Museum and Bloody Brook Tavern. The district has been designated a National Historic Landmark and is a center of heritage tourism in the Pioneer Valley near the Connecticut River.