The iglesia San Ignacio, also known as iglesia del Colegio de San Ignacio, is a Roman Catholic church founded by the Society of Jesus in Santiago, Chile. It is next to the Colegio San Ignacio, and was declared as a National Historic Monument in 2002.^[1]

The church building was built to replace the former Church of the company, destroyed by a fire on 8 December 1863.^[2] It was designed by the Italian architect Eusebio Chelli, who had led the construction of the Iglesia de la Recoleta Dominica and the Iglesia de las Agustinas.^[1] The foundation stone was laid on 15 December 1867.^[3] The construction was stopped and Chelli abandoned the church project in 1872. Three naves were built in clay brick masonry.^[1] On 17 November 1872, the church was blessed by the then Vicar Apostolic of Kansas, John Baptist Miège S.J., who was visiting Chile.^[3]

Between 1899 and 1900, were built two towers — the first reinforced concrete towers in Chile—,^[1] designed by the French architect Eugenio Joannon.^[3] On the other hand, the facade was designed by the Italian architect Ignacio Cremonesi.^[3]

The church building was damaged as a result of the 2010 Chile earthquake. This included cracks in its structure and destruction of architectural ornaments on walls. A restoration project was completed in July 2011.^[2]

The church is Renaissance Revival in style.^[1] On the portico entablature is inscribed: Ad maiorem Dei gloriam ( Ignatius of Loyola's favorite quote), and over the entrance is inscribed the Latin motto: Haec est domus Dei et porta coeli (This is the house of God and the gate of heaven, cite from Genesis 28:17).^[3]

Its two towers are 47 metres high, are 20 tons weight, have a square plan and are topped with a cupola.^[1] The east tower features four clock faces made in Bilbao and installed in 1901 by Evaristo Molina. The west tower has three bells, two of which were made from a bell that hung in the former church, which was destroyed in the before mentioned fire. With a help of the then president Federico Errázuriz Zañartu, along with the minister Aníbal Pinto, the bell was returned to the Jesuits and it was melted down.^[3]

The interior of the church contains a gilded Baroque-Revival-style main altar, and a three-manual pipe organ built by Aristide Cavaillé-Coll, which has over 2,200 pipes and 33 registers, being one of the largest musical instruments in Chile.

• List of Jesuit sites