St. Mary Cathedral Basilica, also known as St. Mary's Cathedral Basilica is a Roman Catholic place of worship situated in Galveston, Texas. It is the primary cathedral of the Archdiocese of Galveston-Houston and the mother church of the Catholic Church in Texas, as well as a minor basilica. Along with the Co-Cathedral of the Sacred Heart in Houston, St. Mary's serves more than 1.5 million Catholics living in the Archdiocese.