O'Conor Don, Hugh (d. 1669), was the son of An Calbhach O'Connor Don (qv) of Ballintober Co. Roscommon, and his wife Mary, daughter of Sir Theobald Bourke (qv), or Tibbot na long (of the ships) At the outbreak of the 1641 rising, Hugh's father assumed leadership of the catholic insurgents in Co. Roscommon and a more nebulous preeminence as ‘king of Connacht’ (deposition of Elizabeth Holliwell), an echo of the former prominence of the O'Connor Don lineage. On Christmas eve 1641 Hugh was present at an attack on the abbey of Roscommon as a colonel in the insurgent army. In the spring of 1642 he was taken prisoner while leading a cattle raid against the protestant outpost of Castlecoote, south of Ballintober on the Galway border. Charles Coote (qv) the younger commanded at Castlecoote and O'Conor was lucky not to be executed out of hand, especially since the wife of one of Coote's officers blamed him for killing her footman. O'Conor was taken to Dublin castle and questioned about this killing and other matters. He justified the rising on the grounds that it was ‘the king's pleasure’ that the Irish ‘should take up arms for that the puritan parliament of England would otherwise destroy them’ (examination of Hugh O'Connor). He defended himself against the murder charge by claiming it was a justifiable act of war against an enemy messenger captured bringing dispatches to Castlecoote. O'Conor was released about a year later, but in the meantime he had been passed over for military office. He did not serve with either of the two Connacht regiments which joined Castlehaven's (qv) Ulster expedition of 1644, in the 1645 expedition to recover Sligo, or in the 1646 campaign which finally secured all of Co. Roscommon for the Confederate Catholics. In July 1652 he was one of five remaining leaders of the Irish forces in Connacht who concluded articles of capitulation with the Cromwellians on the usual condition that he could recruit his followers for the Spanish service. By June 1653 he had raised 200 soldiers but, while preparing to embark, he was again questioned about the alleged murder over ten years before. He was acquitted, and he may have been the ‘H. O'Connor’ who was a captain in O'Rourke's tercio, one of five billeted in north-western Galicia in early 1654.
Ultimately he served as a captain in the duke of Gloucester's regiment in the Spanish Netherlands. The officers of this regiment were overwhelmingly drawn from Connacht and the adjacent parts of Leinster and Ulster. After the restoration of Charles II in 1660 O'Conor was listed as an ‘ensignman’, and this was the basis for his claim for the restoration of his estate from the commissioners appointed to carry out the acts of settlement and explanation. He died in 1669 before the claim was decided. He married (date unknown) Isabella Bourke, and in 1683 their son Hugh óg O'Conor recovered eleven hundred acres of the original estate of some 10,000 acres.