Barry, John (Jack) (d. 1650), army officer, was the son of William Barry; his mother, presumably having remarried, was named in 1661 as Margaret Stephenson, widow. From his grandfather John FitzJames Barry, he inherited extensive properties centred on Liscarroll castle, Co. Cork, which came to be mortgaged to Sir Philip Percival (qv). By 1635 he had begun efforts to recruit Irishmen for Spanish military service, being accorded the command of a regiment in 1636. By 1640 he held the rank of captain in the English army that encountered the Scots but, by November, was reporting that he and other catholic officers were to be cashiered. He was awarded a command in the Irish army in 1641, and was one of the colonels engaged in plans to send disbanded Irish troops into Spanish service that year.
Barry may have been involved in one of the plots that preceded the 1641 rising; certainly he was by then a close associate of James Butler, earl of Ormond (qv) and retained a command in Ormond's Dublin-based army after 1641. From 1643 to 1647 he played a prominent role in Ormond's negotiations with the confederate catholics, acting as liaison at Kilkenny and on occasion travelling to Charles I's court at Oxford. He accompanied the earl of Glamorgan (qv) to Kilkenny in the summer of 1645 and was a signatory of the Glamorgan articles in August. A committed royalist, he left Ireland with Ormond in July 1647 rather than be drawn into either the English parliamentarian or the confederate camps. In February 1648 Ormond dispatched him to Munster to persuade the protestant leader Inchiquin (qv), Murrough O'Brien (1614–73) to declare for the king, and to secure Inchiquin's co-operation with at least some of the confederates, in both of which tasks he succeeded. He took a command in Inchiquin's army with the rank of lieutenant-general but was killed in 1650, apparently as a result of a dispute, almost certainly between 28 May and 16 August. He had married Alice Barry (née Boyle), widow of David Barry (qv), 1st earl of Barrymore, and daughter of Richard Boyle (qv), 1st earl of Cork (her brother later claimed that ‘she was a firm protestant, and he a firm papist, and yet no scruple did arise . . . ’, A collection of the state letters of . . . Orrery (1742), 218), but, leaving no male heir, his property, still mortgaged, came into the hands of Sir John Perceval, heir to Sir Philip.