Shane O'Neill, 3rd Earl of Tyrone

Colonel Shane O'Neill, 3rd Earl of Tyrone (Irish: Seán Ó Néill; Spanish: Juan O'Neill; also anglicised John O'Neill; 28 October 1599 – 29 January 1641) was an Irish-born nobleman, soldier and member of the Spanish nobility who primarily lived and served in continental Europe. He fought for Spain in the Franco-Spanish War (1635–1659) and the Reapers' War.

O'Neill was born during the Nine Years' War in Ireland, the son of Irish confederate leader Hugh O'Neill. Shane O'Neill and his extended family permanently left Ireland in 1607 due to hostility from the English-led government. O'Neill grew up in the Spanish Netherlands. By 1610 he was his father's eldest surviving son, and he eventually moved to Spain to serve in the Spanish army. Though James I of England had attainted his father's title (Earl of Tyrone) in 1614, the Spanish court made O'Neill the third holder of the equivalent Spanish title El Conde de Tyrone. Shane was also de jure 6th Baron Dungannon from 1610 to 1614 by patent of the original earldom.

O'Neill succeeded his elder half-brother Henry as colonel of the original Irish regiment (tercio) in the Netherlands. He was a major supporter of a proposed 1627 Spanish invasion of Ireland. O'Neill professionally clashed with fellow Irish noble-turned-soldier Hugh Albert O'Donnell, Earl of Tyrconnell, even though their fathers had been wartime allies. Following military success at the Siege of Fuenterrabía, O'Neill was appointed a member of the Council of War in 1640. His duties to the Spanish military impeded his lifelong desire to return to Ireland and stage a revolution against English rule. O'Neill died in Catalonia at the Battle of Montjuïc in 1641, and was succeeded by his son Hugo Eugenio O'Neill as both Earl and colonel of the regiment.