The Archive of the Crown of Aragon (ACA) is the historical archive which contains the documents from the institutions of the ancient Crown of Aragon, as well from other historical Spanish collections. The former Royal Archive of Barcelona brings together more than seven centuries of history between its walls.

King Jaume II of Aragon created the Royal Archive of Barcelona in 1318 with the aim of unifying the collection from all the Crown territories. At the beginning, it was mainly to safeguard the written records relating to the Royal Heritage, as well as government and legal documents. During the Bourbon monarchy the building was modernised (1738), a new internal regulations were approved (1754) and with the change of name began the task of incorporating the files of institutions of the Ancient Regime into the collection of the Crown of Aragon.

Until 1993, it was housed in the Palau del Lloctinent, a building constructed between 1549 and 1557 as an extension of the Palau Reial Major in Barcelona. Subsequently, the majority of documents, as well as the task of research, conservation and custody, were moved to the current location on Carrer Almogàvers. The historical headquarters is maintained for the dissemination, through courses and exhibitions, and for ceremonial events.