Suffield is a town in Hartford County, Connecticut, United States. It had once been within the boundaries of Massachusetts. The town is located in the Connecticut River Valley with the town of Enfield neighboring to the east. In 1900, 3,521 people lived in Suffield; as of the 2010 census, the population was 15,735. The town center is a census-designated place listed as Suffield Depot in U.S. Census records.Bordering Massachusetts, Suffield is part of the Springfield, Massachusetts NECTA. Suffield is only 8 miles from Springfield, and is more oriented toward it than toward Connecticut's capital of Hartford, which lies 16 miles to the south.