Granville Mercer Williams SSJE (December 31, 1889 — August 11, 1980) was an American Anglo-Catholic priest, monk, and author during the twentieth century.
Williams was born in Utica, New York to a prominent New England family and studied at Columbia University (1911) and Harvard Divinity School (1920).
He was also involved extensively in Anglican religious life for women, serving as chaplain to the American All Saints Sisters of the Poor from 1939 to 1969, and warden of the Order of S. Anne in Arlington, Massachusetts from 1939 until his death in 1980.
He was president of the Catholic Clerical Union from 1932 to 1941, and a member of the American council of the Confraternity of the Blessed Sacrament from 1952 to 1965.
Williams's father, Granville Whittlesey Williams (1859-1947), president of the Murray Hill Iron Company, was a significant source of the Cowley Fathers' wealth in the United States in the twentieth century.