A military coup in Argentina ousts Ramón Castillo.

The 1943 Argentine Revolution was a coup d'état on 4 June 1943 that ended the government of Ramón Castillo, who had been fraudulently elected to the office of vice-president before succeeding to the presidency in 1942 as part of the period known as the Infamous Decade. The coup d'état was launched by the lodge "United Officers' Group" (GOU), a secret military organization of nationalist nature. Although its soldiers shared different views of nationalism: there were Catholic nationalists, Radicals, military with a more pragmatic approach, and even fascists. The military was opposed to Governor Robustiano Patrón Costas, Castillo's hand-picked successor, a major landowner in Salta Province and a primary stockholder in the sugar industry. The only serious resistance to the military coup came from the Argentine Navy, which confronted the advancing army columns at the Navy Petty-Officers School of Mechanics.

Argentina, officially the Argentine Republic, is a country in the southern half of South America. It covers an area of 2,780,085 km² (1,073,397 sq mi), making it the second-largest country in South America after Brazil, the fourth-largest country in the Americas, and the eighth-largest country in the world. Argentina shares the bulk of the Southern Cone with Chile to the west, and is also bordered by Bolivia and Paraguay to the north, Brazil to the northeast, Uruguay and the South Atlantic Ocean to the east, and the Drake Passage to the south. Argentina is a federal state subdivided into twenty-three provinces, and one autonomous city, which is the federal capital and largest city of the nation, Buenos Aires. The provinces and the capital have their own constitutions, but exist under a federal system. Argentina claims sovereignty over the Falkland Islands, South Georgia and the South Sandwich Islands, the Southern Patagonian Ice Field, and a part of Antarctica.

Ramón Antonio Castillo Barrionuevo was President of Argentina from 1942 to 1943. He took office after the resignation of President Roberto María Ortiz, under whom he was the Vice President. He was a leading figure in the period known as the Infamous Decade, characterised by electoral fraud, corruption and rule by conservative landowners heading the alliance known as the Concordancia.