The building of the Municipality of Santiago is the seat of the Illustrious Municipality of Santiago. It is located on the north side of the Plaza de Armas, on the corner of Monjitas Street and 21 de Mayo Avenue, next to the former Royal Audience Palace, which today houses the National Historical Museum.

Since Santiago's foundation, this site has been used to house a public building, originally occupied by the city hall and the old colonial prison. A first building was built between 1578 and 1647. In 1679 the building was demolished and later, between 1785 and 1790, a second building was constructed by the Italian architect Joaquín Toesca, now in neoclassical style.

A fire in 1891 forced a reconstruction carried out by the architect Eugène Joannon. The third building on the site - which is still standing - was inaugurated in 1895 and officially declared as the seat of the communal administration. In 1976 it was declared a historical monument.