1864 in Argentina

Events in the year 1864 in Argentina.

Incumbents

 * President: Bartolomé Mitre
 * Vice President: Marcos Paz

Governors

 * Buenos Aires Province: Mariano Saavedra
 * Cordoba: Roque Ferreyra (starting month unknown)
 * Mendoza Province: Carlos González
 * Santa Fe Province: Patricio Cullen

Vice Governors

 * Buenos Aires Province: vacant

Events

 * 10 August – Uruguayan War: War breaks out between Brazil and Uruguay, despite negotiations involving Argentine Foreign Minister Rufino de Elizalde.
 * 25 October – establishment of General Las Heras Partido
 * 13 December – Paraguayan War: Paraguay declares war on Brazil; war with Argentina follows three months later.
 * The classic aperitif Hesperidina is invented by American immigrant Melville Sewell Bagley in Buenos Aires.

Deaths

 * 30 October – Jonas Coe ("Comodoro Juan Coe"), US naval commander and supporter of Juan Manuel de Rosas (born 1805).