The Reverend Endicott Peabody (May 31, 1857 – November 17, 1944) was the American Episcopal priest who founded the Groton School for Boys (known today simply as Groton School), in Groton, Massachusetts in 1884. Peabody also founded St. Andrew's Episcopal Church in Ayer, Massachusetts, in October 1889. Peabody served as headmaster at the school from 1884 until 1940 and also served as a trustee at Lawrence Academy at Groton.