The Namacpacan Church also known as the Santa Catalina de Alejandria Church is a Roman Catholic church located in Luna (formerly Namacpacan), La Union, Philippines under the jurisdiction of the Roman Catholic Diocese of San Fernando de La Union. Formerly called as Luna Church, the church is placed under the advocacy Saint Catherine of Alexandria in 1690 and known for its devotion to the Our Lady of Namacpacan. The church was declared a National Cultural Treasure by the National Museum of the Philippines.