The Irish surname Dooly is an anglicized form of the Gaelic name  Ó Dubhlaoich meaning “descendant of Dubhlaoch,” a personal name composed of the elements dubh ‘meaning “black” and  laoch meaning “champion, or hero.” “Son of the dark haired hero.” The Dooly clan chiefs were also known as the Lords of Fertullagh in County Westmeath, in medieval times. In the Census of Ireland in 1659 they were also shown to be numerous in Counties Laois and Offaly, and to this day they are most numerous in this area in the Center of Ireland.