The Roman Catholic Archdiocese of Boston (Latin: Archidioecesis Bostoniensis) is an ecclesiastical territory or Archdiocese of the Roman Catholic Church in the New England region of the United States. Its present territory spans the whole of Essex County, Middlesex County, Norfolk County, and Suffolk Count, and also all of Plymouth except the towns of Marion, Mattapoisett, and Wareham in the Commonwealth of Massachusetts. It is led by a prelate archbishop who serves as pastor of the mother church, Cathedral of the Holy Cross in the South End of Boston.