The Roman Catholic Diocese of Saint John's—Basseterre (Latin: Dioecesis Sancti Ioannis Imatelluranus) is a diocese of the Latin Rite of the Roman Catholic Church in the Caribbean. The diocese encompasses the islands of Antigua and Barbuda, Saint Kitts and Nevis, Montserrat, Anguilla and the British Virgin Islands. The diocese is a suffragan of the Archdiocese of Castries, and a member of the Antilles Episcopal Conference.
The diocese was erected in January 1971, and unlike many other dioceses, it has two cathedrals: Holy Family Cathedral in St. John's, Antigua, and the Co-Cathedral of the Immaculate Conception in Basseterre, St. Kitts.
Both cathedrals are the seat of the bishop, the Most Rev. Gabriel Malzaire.He was born in Dominica and preceded after archbishop, the Most Rev. Donald J. Reece in 2009.