Recorded in a wide range of spelling including O'Dolan, Dolan, Doolan, Dooland, Doolin, Doolen, Doulin, Doyland, Doylend, and many others, this is an Irish surname of great antiquity. Formerly recorded in the Gaelic spelling of O'Dobhailen, the nameholders originate from the baronies of Clonmacnowen found in two quite separate counties, Galway and Roscommon.The derivation of the name is probably from the Norman "Robert", of which one of the nickname forms is "Dob". Robert as a name being originally introduced into Ireland in the year 1170, by Strongbow, earl of Pembroke, when he invaded the country. Irish surname nearly always commenced with a chief and his nickname. Sometimes these nicknames were at best robust, or at worst obscene, although this does not seem to have worried the original nameholders. In this case the derivation if correct, suggests that the first nameholder may have been of Norman-English stock, but if so, as happened with several other tribes, within a fairly short space of time, the clan became fully Gaelicised. In the 20th century the nameholders are to be found in Counties Fermanagh, Leitrim, and Cavan, as well as their original homelands. Examples of the surname recording include Letitia Dolan, the daughter of David Dolan, christened at St Catherines church, Dublin, on August 6th 1707, and Mary Doolan, who married David Smyth at Ardfert, County Kerry, on Christmas Day, 1817.