The Roman Catholic Diocese of Biloxi was established on March 1, 1977, when it was split from the Roman Catholic Diocese of Jackson. The Diocese of Biloxi encompasses the seventeen southern Mississippi counties of Covington, Forrest, George, Greene, Hancock, Harrison, Jackson, Jefferson Davis, Jones, Lamar, Lawrence, Marion, Pearl River, Perry, Stone, Walthall and Wayne. The diocese is part of the ecclesiastical province of Mobile and is populated with approximately 70,630 Catholics from the Alabama-Mississippi state line to the Mississippi-Louisiana state line and extending north of Laurel into Jones and Wayne counties.
The Cathedral of the Nativity of the Blessed Virgin Mary, in Biloxi, Mississippi, serves as the Episcopal see.
The Administrative Office of the Diocese of Biloxi is located at 1790 Popps Ferry Road, Biloxi, MS 39532.