José Francisco de San Martín (c. 1778 – 17 August 1850), known simply as José de San Martín, is an Argentine general and the prime leader of the southern part of South America's successful struggle for independence from the Spanish Empire.

Born in Yapeyú, Corrientes, in modern Argentina, he leaves his mother country at the early age of seven and studies in Málaga, Spain.

In 1808, after joining Spanish forces in the Peninsular War against the French, San Martín starts making contact with South American supporters of independence from Spain.

In 1812, he sets sail for Buenos Aires from England and offers his services to the United Provinces of South America, present-day Argentina.

After the Battle of San Lorenzo of 1813, and some time on command of the Army of the North (Spanish: Ejército del Norte) during 1814, he begins to put into action his plan to defeat the Spanish forces that menace the United Provinces from Upper Peru, making use of an alternative path to the Viceroyalty of Peru.

This objective first involves the establishment of a new army, the Army of the Andes, in Cuyo Province, Argentina.

From there, he leads the Crossing of the Andes to Chile, and prevailsover the Spanish forces at the Battle of Chacabuco and the Battle of Maipú (1818), thus liberating Chile from royalist rule.

Then he sets sail to attack the Spanish stronghold of Lima, Peru, by sea.

On 12 July 1821, after seizing partial control of Lima, San Martín is appointed Protector of Peru (Protector del Perú), and Peruvian independence is officially declared on 28 July.

On 22 July 1822, after a closed-door meeting with fellow libertador Simón Bolívar at Guayaquil, Ecuador, Bolívar takes over the task of fully liberating Peru.

San Martín unexpectedly leaves the country and resigns the command of his army, excluding himself from politics and the military, and moves to France in 1824.

The details of the 22 July meeting will be a subject of debate by later historians.

San Martín is regarded as a national hero of Argentina and, together with Simon Bolívar, one of the liberators of Spanish South America.

The Order of the Liberator General San Martín (Orden del Libertador General San Martín), created in his honor, is the highest decoration conferred by the Argentine government.