The Argentine Confederation (Spanish: Confederación Argentina) is the last predecessor state of modern Argentina; its name is still one of the official names of the country according to the Argentine Constitution, Article 35.

It is the name of the country from 1831 to 1852, when the provinces are organized as a confederation without a head of state.

The governor of Buenos Aires Province (Juan Manuel de Rosas during most of the period) managea foreign relations during this time.

Under his rule, the Argentine Confederation resista attacks by Brazil, Bolivia, Uruguay, France and the UK, as well as other Argentine factions during the Argentine Civil Wars.

Rosas is ousted from power in 1852 by Justo José de Urquiza, after the battle of Caseros.

Urquiza convenes the 1853 Constituent Assembly to write a national constitution.

Buenos Aires resists Urquiza and seceded from the Confederation in 1852, becoming the State of Buenos Aires; the province will return to Argentina in 1861.