Family History and Genealogy Resources by Surname
Halloran Surname Origin
(Origin Irish) From the gaelic Ó hAllmhuráin meaning the descendant a stranger from overseas).
Source: An Etymological Dictionary of Family and Christian Names With an Essay on their Derivation and Import; Arthur, William, M.A.; New York, NY: Sheldon, Blake, Bleeker & CO., 1857.
Halloran Surname Meaning and Family Facts
There is more to Halloran family history than the origin of your surname:
A Halloran Family History Thought:
'There is no king who has not had a slave among his ancestors, and no slave who has not had a king among his.' --Helen Keller