Byfield is a village (also referred to as a "parish") in the town of Newbury, in Essex County, Massachusetts, United States.
The village post office was established January 11, 1826, with Benjamin Colman as the first postmaster.
It also contains the Newbury town library and Triton Regional High School, which serves three towns (Salisbury, Rowley and Newbury), Adelynrood Retreat & Conference Center, run by the Society of the Companions of the Holy Cross as well as the prep school The Governor's Academy (previously known as Governor Dummer Academy after William Dummer, one of the founders of the Newbury area).
An arts center and Pearson's deer farm are also located in Byfield.
The short story "Snowball," by mystery writer Ursula Curtiss, takes place in Byfield.