Roman Catholic Diocese of San Fernando de La Union

The Diocese of San Fernando de La Union (Dioecesis Ferdinandopolitana ab Unione) is a Latin Church ecclesiastical territory or diocese of the Catholic Church in the Philippines. The diocese was established in 1970 from the Archdiocese of Nueva Segovia. It is a suffragan in the ecclesiastical province of the metropolitan Archdiocese of Lingayen-Dagupan.