(O)CULLINAN, Quillinane.  Cullinan is the most anglicized spelling of the name Ó Cuileannáin in Co. Clare and Cullinane in Co. Cork and east Munster.  The prefix O is seldom found with Cullinan or Cullinane nowadays.  One important sept so called originated in Tirconaill (Donegal), but there the name has been changed to Cullen.  Up to the end of the seventeenth century they were still using the form O'Cullinan.  they were closely associated with the O'Donnells and their seat was at Mullinashee.  One of their sixteenth century chiefs was remarkable on account of the careers of his sons, of whom one was a bishop and six were abbots.  Dr. John Cullinan (1585-1653), was Bishop of Raphoe and suffered much prsecution as such:  he was a prominent support of Rinnuccini at the Confederation of Kilkenny.  His brother Glaisne O'Cullinan (1558-1584), Cistercian Abbot of Boyle, was martyred.  The O'Cullinanes of Co. Cork are a branch of the Corca Laidhe and their territory was in the barony of Barryroe.  The Civil Survey and the 1659 census indicate that the name was very numerous in Co. Cork in the seventeenth century not only in Barryroe but also in the surrounding baronies;  two from Kinalea were among the Irish who sailed for Spain after the Battle of Kinsale.  At that time, as today, branches of the sept were well established in Co. Clare and in Co. Waterford; in the latter the spelling of name was then Quillinane, a form still occasionally met with in Munster.

Cormac Mac Cuilleannáin, King and Bishop of Cashel, who was slain in battle 908 A.D., is famous as the compiler of the genealogical tract called the "Psalter of Cashel" and as the first language lexicographer.  He cannot, however, properly be called a Cullinane because he lived before the era of surnames;  this father's christian name was Cuileanán. 

The Cullinan family may have been associated with the town since 1674, when Connor O'Cullanane was fined by the Manor Court for not keeping to the terms of his lease.  In 1824, Michael was an attorney in Church Street and John Cullinan was a publican in Mill Street.  Michael Cullinan was recorded in the membership lists of the Ennis Freemason as "a new name given at attending"  in 1842; William Cullinan and John Cullinan were initiated in 1867; Dr. Comac Cullinan joined the order in 1871; Fred G. Cullinan was admitted in 1887....In 1846, Michael Cullinan was practicing law in Jail Street; Denis Cullinan was a blacksmith in Lifford; Martin Cullinan was a boot an shoe maker in Church Street, John Cullinan of Church Street was a linen and woolen draper and a haberdasher; and Patrick M. Cullinan of Jail Street was a physician...in 1886, Patrick Maxwell Cullinan was practicing medicine in Harmony House; Michael and William Cullinan were also doctors;...in 1893, James Cullinan had a boot and shoe warehouse in O'Connell Square; R. Cullinan was a grocer in Mill Street; Thomas Cullinan was a vintner in Mill Street...by 1918, F.F. Cullinan was dealing with customers from his telephone number, in 1925, John Cullina was a solicitor...Denny Cullinan started a hackney firm...in 1996, Martin Cullinan was the propietor of Club Dangan in 14 O'Connell Street...