The Diocese of Brooklyn is a Latin Church ecclesiastical territory or diocese of the Catholic Church in the U.S. state of New York. It is headquartered in Brooklyn and its territory encompasses the New York City boroughs of Brooklyn and Queens. The Diocese of Brooklyn is a suffragan diocese in the ecclesiastical province of the metropolitan Archdiocese of New York. The diocesan cathedral is the Cathedral Basilica of St. James in Downtown Brooklyn and its co-cathedral is the Co-Cathedral of St. Joseph in Prospect Heights. The current Bishop of Brooklyn is Robert J. Brennan.

The Archdiocese of New York is a Latin Church ecclesiastical territory or archdiocese of the Catholic Church located in the State of New York. It encompasses the boroughs of Manhattan, the Bronx and Staten Island in New York City and the counties of Dutchess, Orange, Putnam, Rockland, Sullivan, Ulster, and Westchester to the north of the city. It does not include the New York City boroughs of Brooklyn or Queens, which are part of the Diocese of Brooklyn.