Henry O'Neill (soldier)

Henry O'Neill
5th Baron Dungannon (unrecognised)
Tenure1609–1610
PredecessorHugh O'Neill, 4th Baron Dungannon
SuccessorShane O'Neill, 6th Baron Dungannon
Bornc.1586
Ulster, Ireland
Died25 August 1610 (aged 23)
Aranda de Duero, Spain
BuriedMadrid, Spain
IssueNone
FatherHugh O'Neill, Earl of Tyrone
MotherSiobhán O'Donnell

Colonel Henry O'Neill (Irish: Enri Ó Néill; Spanish: Enrique Oneil; c.1586 – 25 August 1610) was an Irish-born soldier and nobleman who served with the Spanish army in the Eighty Years' War.

In 1600 he was relocated to Spain to strengthen relations between his father, Irish confederacy leader Hugh O'Neill, and the Spanish government. Following the end of the Nine Years' War (1603) and the Anglo-Spanish War (1604), Henry continued to live in Spain and expressed interest in military service. English officials feared his entrance into the Spanish military could renew conflict. Nevertheless, in 1605 Henry was made colonel of the first Irish regiment in the Spanish army. He served for many years in the Low Countries, before dying in Spain of illness, aged 23.

Henry was de jure 5th Baron Dungannon by the patent of the earldom, though he was never recognised as such by the Irish House of Lords.