The British invasions of the Río de la Plata, a series of unsuccessful British attempts to seize control of the Spanish colonies located around the La Plata Basin in South America (today Argentina and Uruguay), take place between 1806 and 1807, as part of the Napoleonic Wars, when Spain is an ally of France.The invasions are in two phases.

A detachment from the British Army occupies Buenos Aires for 46 days in 1806 before being expelled.

In 1807, a second force occupies Montevideo, following the Battle of Montevideo (1807), remaining for several months, and a third force makes a second attempt to take Buenos Aires.

After several days of street-fighting against the local militia and Spanish colonial army, in which half of the British forces in Buenos Aires are killed or wounded, the British are forced to withdraw.The resistance of the local people and their active participation in the defense, with no direct support from the Spanish Kingdom, are important steps toward the May Revolution in 1810, and the Argentine Declaration of Independence in 1816.