O'Halloran
An Irish surname meaning a descendant of a man named Halloran, from an older Gaelic personal name associated with strangeness or foreignness.
The #9,839 most common surname in the United States (2010 Census) — about 1 in every 93,872 Americans shares it.
Etymology
O'Halloran is the Anglicized form of the Irish Gaelic surname Ó hAllmhuráin. The prefix Ó means 'descendant of,' while the personal name behind the surname is usually connected with allmhurach, a word meaning 'foreign' or 'strange.' In that sense, the name likely began as a family designation referring to an ancestor with a byname linked to being an outsider or foreigner.
History
The surname is traditionally associated with County Clare and the west of Ireland, where the O'Hallorans were an established Gaelic family. Like many Irish surnames, it was later Anglicized in several spellings, with the apostrophe form becoming common in English. Bearers of the name spread widely through emigration, especially in the 19th and 20th centuries, giving the surname a modest but recognizable presence in the United States and other English-speaking countries.
Origin
Regions
Variant spellings
Fun fact
The surname is often treated as a classic example of an Irish name that preserves an older Gaelic clan prefix, Ó, even when the apostrophe is dropped in everyday use.