Lower, Mark A (1860) Patronymica Britannica: a dictionary of the family names of the United Kingdom. London: J.R. Smith. Public Domain.
OREILLY
There are approximately 4,122 people named Oreilly in the UK. That makes it the 2,519th most common surname overall. Out of every million people in the UK, approximately 65 are named Oreilly.
Region of origin
British Isles
Country of origin
Ireland
Language of origin
Gaelic
Religion of origin
Christian
Classification
Celtic
From name of parent
Related and similar surnames
AureliAurelly
Aurely
Aurelli
Aurevilly
Auriell
Ohreilly
O'Reilly
O'Rielly
O'Railly
O'Relly
O'Reelly
O'Really
O'Reillly
O'Reily
O'Reilley
O'Reiley
O'Riely
O'Rally
O'Rielley
O'Rely
The Oreilly surname in historical dictionaries
Patronymica Britannica (1860)
O'REILLY. The family claim descent "from Brian, the fourth" Milesian king pf Connaught. The name was derived frOm an ancestor called Ragallagh — by softened pronunciation Reilly — who lived at tlie commencement of the eleventh century. His grandson Targaille, prince of East Brefny, was the first who used the name of Ua Ragallagh or O'Reilly." B.L.G.