The British Legion or British Legions were foreign volunteer units which fought under Simón Bolívar against Spain for the independence of Colombia, Venezuela, and Ecuador, and under José de San Martín for the independence of Peru, in the Spanish American wars of independence. Venezuelans generally called them the Albion Legion. They were composed of over seven thousand volunteers, mainly Napoleonic War veterans from Great Britain and Ireland, as well as some German veterans and some locals recruited after arriving in South America. Volunteers in the British Legion were motivated by a combination of both genuine political conviction and mercenary motives.

The Spanish American wars of independence took place throughout Spanish America during the early 19th century, with the aim of political independence from Spanish rule. Struggles for sovereignty in both hemispheres began shortly after the outbreak of the Peninsular War as a front in the larger Napoleonic Wars, between royalists who favored a unitary monarchy, and patriots who favored either plural monarchies or republics. Thus, the strict period of military campaigns would go from the Battle of Chacaltaya (1809), in present-day Bolivia, to the Battle of Tampico (1829) in Mexico.