Sagrario Cathedral, Catholic cathedral in Rancagua, Chile

Sagrario Cathedral is a Catholic church facing the Plaza de los Héroes in Rancagua, Chile. Built of lime and brick, it measures 59 varas long by 24 wide, with three naves and five doors. The French architect Juan Herbage drew the 1861 plans, and the Italian Eusebio Chelli completed the project and laid out the towers, built in 1937.

The parish was erected in 1550 by Diego de Medellín, Bishop of Santiago, and its first church was damaged during the Battle of Rancagua on 1–2 October 1814. A commission was named on 30 August 1854 to build a replacement; plans came from architect Juan Herbage in 1861, and Eusebio Chelli laid out the towers. The new parish church was blessed on 30 January 1876 under priest Rafael Jofré, and it was consecrated a cathedral on 21 October 1926 by Rafael Lira Infante.

The cathedral is also the parish church El Sagrario, a name it kept after being separated from Santiago's El Sagrario parish. It was consecrated as a cathedral on 21 October 1926 by Monsignor Rafael Lira Infante, exactly 50 years after the new parish church was blessed in 1876. The building is listed as an Inmueble de Conservación Histórica.

The cathedral faces the Plaza de Los Héroes, the square where the 1814 Battle of Rancagua was fought, so it is reached on foot from anywhere in the historic centre. It is an active parish, so visits fit around mass times. The building is listed as an Inmueble de Conservación Histórica, which limits alterations to its fabric.

The 2010 earthquake caused serious but repairable damage, so demolition was ruled out. Restoration began in August 2010 with an estimated cost of over 400 million pesos, and the cathedral reopened on 21 April 2011, exactly 85 years after its 1926 consecration as a cathedral.