Plaza San Lorenzo Ruiz or Plaza Lorenzo Ruiz is a major public square in Binondo, Manila, bounded by Quintin Paredes Street (formerly Calle Rosario) to the east and Juan Luna Street (formerly Calle Anloague) to the west, parallel to the Estero de Binondo. It is the plaza that fronts the Minor Basilica of San Lorenzo Ruiz (Binondo Church), one of the main churches of the City of Manila, and is considered the center of Binondo as a whole.
Originally called the Plaza de Binondo, and then Plaza Carlos IV after Charles IV of Spain, the plaza was eventually renamed Plaza Calderón de la Barca (often shortened to Plaza Calderón), after the famous Spanish playwright. It is believed that the plaza may have been renamed after Calderón either by the then-sitting Governor-General, or by the Dominican friars who were at the time running the Binondo Church, who had adored his works. The plaza was renamed after Lorenzo Ruiz, one of the Martyrs of Japan and the protomartyr of the Philippines, on September 12, 1981, by virtue of Batas Pambansa Blg. 133.