The Second Desmond rebellion (1579–1583) was the more widespread and bloody of the two Desmond Rebellions launched by the FitzGerald dynasty of Desmond in Munster, Ireland, against English rule in Ireland. The second rebellion began in July 1579 when James FitzMaurice FitzGerald, landed in Ireland with a force of Papal troops, triggering an insurrection across the south of Ireland on the part of the Desmond dynasty, their allies and others who were dissatisfied for various reasons with English government of the country. The rebellion ended with the 1583 death of Gerald FitzGerald, 15th Earl of Desmond and the defeat of the rebels.
The rebellion was in equal part a protest by feudal lords against the intrusion of central government into their domains, a conservative Irish reaction to English policies that were altering traditional Gaelic society; and a religious conflict, in which the rebels claimed that they were upholding Catholicism against a Protestant queen who had been pronounced a heretic in 1570 by the papal bull Regnans in Excelsis.
The result of the rebellions was the destruction of the Desmond dynasty and the subsequent Munster Plantations – the colonisation of Munster with English settlers. In addition the fighting laid waste to a large part of the south of Ireland. War-related famine and disease are thought to have killed up to a third of Munster's pre-war population.