O’Reilly is the 11th most common surname in Ireland. The name means ‘extroverted one’ and is derived from the old Irish name O’Raghaillach, which means ‘descendent of Raghaillach’.
‘Riley’ has become a popular first name for both boys and girls in the United States.
There are also variations of the name such as Riley, Rily, Briley and Brily.
In the 15th century the O’Reillys produced their own coins. A ‘Reilly’ is still used as a name for a coin of significant value.
The motto on the O’Reilly coat of arms says ‘Foutitudine et prudentia’ which means ‘With fortitude and prudence’.
Related to the O’Connors
They have close links with the O’Connor kings of Connacht. Both families have a common ancestor in Maolmordha. Maolmordha was the great grandfather of Raghaillach, who was the forefather of the O’Reillys.
The O’Reilly sept once ruled Breffny, which was an ancient Gaelic kingdom which covered the area that is now Co Cavan and parts of the surrounding counties, particularly Co Westmeath.
The first recorded spelling of the name O’Reilly was Cathal O’Reilly who was Prince of Breffny in 1237.
Video of the story of the O’Reilly name
St Mary’s Abbey in Cavan
The O’Reillys were a very religious family and even set up a Franciscan Friary in Cavan, St Mary’s Abbey. It was founded by Giolla Iosa O’Reilly in the early 12th century. It was burned down by the English in 1468 but soon rebuilt by the Irish. It was an active friary until 1826.
All that remains of the abbey today are the three story tower, the graveyard and a section of the wall. Myles “the slasher” O’Reilly, who was a hero in the Battle of the Bridge of Finea in 1644 is buried in the graveyard, as is 1640 Rebellion leader, Eoghan Roe O Neill.
Thirty nine abbots who worked at St Mary’s were O’Reillys. The family has also produced Archbishops in Co Armagh.
John Boyle O’Reilly was born in Co Louth 1844. He became involved in Fenian military groups and was deported to Australia. He escaped and headed to America where he settled in Boston and became editor of the Pilot newspaper. Before long the Pilot became one of the most read publications in the entire country.
John Rielly was leader of the San Patricios, who were a group of Irish Americans who deserted the US Army during the 1846-48 Mexican war and went to fight for the Mexicans.
They were unhappy with the way Irish American Catholics were treated by the rest of the US Army and also disagreed with brutality towards Mexican citizens, priests and nuns. Today there is a sculpture of John Reilly as well as the flag of the San Patricios in his home town of Clifden, Co Galway.
Famous O’Reillys throughout the world
James F. Reilly was an astronaut born in 1954 in Idaho. Throughout his career he spent over 850 hours in space which included five spacewalks.
Paddy Reilly was a folk singer born in Dublin in 1939. He had several years of success as a solo performer in Europe the US and Australia before joining the Dubliners as replacement for Ronnie Drew.
His namesake was a coach driver who became the subject of the famous Percy French song, Come Back Paddy Reilly to Ballyjamesduff.
Hollywood actor John C. Reilly has appeared in several hit movies including Gangs of New York, The Hours and Step Brothers. He was nominated for an Oscar for Best Supporting Actor for his performance in Chicago.