The Roman Catholic Diocese of Rockville Centre, New York is a religious corporation serving approximately 1.4 million Catholics across Nassau and Suffolk counties on Long Island. Established in 1957, it ranks as the eighth-largest diocese in the United States by Catholic population. The organization oversees 135 parishes, 39 schools, and 15 charitable or religious-service affiliates. Its workforce includes 553 priests, 801 religious women, 34 brothers, and 285 permanent deacons, providing extensive educational, social, and ministerial services.