The Province of Cuyo was a historical Province of Argentina. Created on 14 November 1813 by a decree issued by the Second Triumvirate, it had its capital on Mendoza, and was composed by the territories of the present Argentine Provinces of Mendoza, San Juan and San Luis.
For centuries in colonial times, the region was part of the Captaincy General of Chile, at the time part of the Viceroyalty of Peru. In 1778, the territories under the jurisdiction of Santiago de Chile were divided: Cuyo was transferred to the Viceroyalty of the Río de la Plata, the last Viceroyalty of the Spanish Empire, created shortly before (in 1776) and with capital in Buenos Aires, while the territories West of the Andes of the Captaincy General of Chile remained part of the Viceroyalty of Peru.
Its first and foremost Governor was José de San Martín, who devoted his Governorship to the creation of the Army of the Andes and the preparations for the Crossing of the Andes campaign.