1851 in Argentina

Events in the year 1851 in Argentina.

Incumbents

 * Governor of Buenos Aires Province: Juan Manuel de Rosas (de facto Head of State of Argentina)
 * Governor of Cordoba: Manuel López
 * Governor of Santa Fe Province: Pascual Echagüe then Domingo Crespo

Events

 * May 1 – governors Justo José de Urquiza of Entre Rios and Benjamin Virasoro of Corrientes rise up against Rosas
 * May 29 – Corrientes and Entre Rios enter into alliance with Uruguay and Empire of Brazil
 * August 18 – Rosas declares war on Empire of Brazil

Births

 * March 19 – Roque Sáenz Peña, President 1910–1914