Thomas Dillon, 4th Viscount Dillon

Thomas Dillon, 4th Viscount Dillon PC (Ire) (1615–1673) held his title for 42 years that saw Strafford's administration, the Irish Rebellion of 1641, the Irish Confederate Wars and the Cromwellian Conquest of Ireland. He was a royalist and supported Strafford and Ormond. He sided with the Confederates for a while but was a moderate who opposed Rinuccini, the papal nuncio.

Lord Dillon fled the field at the Battle of Dungan's Hill (1647) and did not rescue Ormond at the Battle of Rathmines (1649). However, he defended Athlone successfully against Ireton in 1650.