Byfield is a village (also referred to as a "parish") in the town of Newbury, in Essex County, Massachusetts, United States. It borders West Newbury, Georgetown, and Rowley. It is located about 30 miles north-northeast of Boston, along Interstate 95, about 10 miles south of the border between New Hampshire and Massachusetts. The ZIP Code for Byfield is 01922. Byfield was also the home of Governor William Dummer. The village post office was established January 11, 1826 with Benjamin Colman as the first postmaster.