St. Ann & the Holy Trinity Church is a historic Episcopal church at the northwest corner of Montague and Clinton Streets in the Brooklyn Heights neighborhood of Brooklyn in New York City. It is the co-cathedral of the Episcopal Diocese of Long Island.

Brooklyn Heights is a residential neighborhood within the New York City borough of Brooklyn. The neighborhood is bounded by Old Fulton Street near the Brooklyn Bridge on the north, Cadman Plaza West on the east, Atlantic Avenue on the south, and the Brooklyn–Queens Expressway or the East River on the west. Adjacent neighborhoods are Dumbo to the north, Downtown Brooklyn to the east, and Cobble Hill and Boerum Hill to the south.