(O) FLYNN, O'Lynn.  The surname O'Flynn is derived from the Gaelic personal name Flann; the adjective flann denotes a dull red colour and means ruddy when applied to persons.  Ó Floinn is the form of the surname in Irish.  It is one of those which arose independently in several parts of the country and, as might be expected, is widely distributed.  It ranks forty-first in the list of most numerous surnames in Ireland with an estimated total of thirteen thousand persons.  These are found chiefly in two main areas - Cork and Waterford in the south, and on the borders of Connacht and Ulster in the adjacent counties of Roscommon, Leitrim and Cavan.  Two of the O'Flynn septs originated in Co. Cork.  Of these O'Flynn of Ardagh Castel (between Skibbereen and Baltimore) was a branch of the Corca Laoidhe; and the O'Flynns of Muskerry were lords of Muskerrylinn (Muscraidhe Ui Fhloinn), i.e. the country between Ballyvourney and Blarney.  They were pushed thence by the MacCarthys and moved to a more easterly location.  The most important of the Connacht septs of the name was O'Flynn of Kiltullagh and Kilkeevin in Co. Roscommon.  In the same county O'Flynns were erenaghs of the Church of St. Dachonna near Boyle.  The head of the family had the peculiar privilege of mounting the same steed as the royal O'Connor.  Further west at Errew on the shore of Lough Conn was another erenagh family of O'Flynn.  Another sept of ÓFloinn was at one time famous in Ulster.  The possessed a territory in southern Armagh between Lough Neagh and the sea were the senior branch of Clanna Rury of Ulidia, tracing their descent back to Colla Uais, King of Ireland in the fourth century.  The F of Ó Floinn was aspirated in modern Ulster Irish, with the result that the name became Ó Loinn and the anglicized from O'Lynn in the north.

Numerous though they are and were, few O'Flynns have found a place in the pages of Irish history.  Fiacha O'Flynn (also called MacFlynn), Archibishop of Tuam was the emissary of the Irish Church to England in 1255.  Among the Irish in France, however, they have been prominent both as ecclesiastics and as officers of the Irish Brigade.  In modern times Rev. Jeremiah O'Flynn (1788-1831) was a Franciscan friar whose interesting and stormy career relates chiefly to the early church in Australia and later in the USA.  Edmund James Flynn (b. 1847) was Premier of Quebec and William James Flynn (1867-1928) was a famous American Detective.

Of the O'Lynns the most noteworthy was Father Donough O'Lynn, O.P., who was martyred in 1608 at the age of 90.  "Father O'Flynn", of the ever populr song, was a fictitious character.  The northern form of the name is also popularized in a well know Irish song, "Brian O'Lynn."  John Flynn (1880-1951) Presbyterian missionary (with an Irish Catholic background) is regarded by the Australians of all creeds as one of the finest men their country has produced.  He founded the Flying Doctor Service and was known as "Flynn of the Inland."

In Irish the name is Ó Floinn, from the adjective flann,  meaning 'reddish' or 'ruddy', which was extremely popular as a personal name in early Ireland.  As might be expected, this popularity led to the surname coming into being independently in several different parts of the country, including Clare, Cork, Kerry, Mayo, Roscommon, Cavan, Antrim and Monaghan.  The most historically important of these were the families originating in Cork and Roscommon, with the former ruling over a territory in Muskerry between Ballyvourney and Blarney, and the latter centred on the area of north Roscommon around the modern town of Castlerea.  In Co. Antrim the Irish version of the name was Ó Fhloinn, with the initial "F" silent, so that the anglicised version became 'O'Lynn', or simoly 'Lynn".  The O'Lynns ruled over the lands between Lough Neagh and the Irish Sea in S\south Antrim.  (O')Flynn is now numerous throughout Ireland, though significant concentrations are still to be found in north Connacht and the Cork/Waterford areas, roughly corresponding to the original homelands.

(O) Flynn, Flyng.  Ó Floinn (flann, ruddy).  This numerous and widespread name orignated in a number of different places, including Kerry and Clare.  Of the two in Co. Cork one was a branch of the Corca Laoidhe, the other, lords of Muskerylinn (Musiscre Ui Fhloinn); in north Connacht the O'Flynns were leading men under the royal O'Connors, and there was also an erenagh family there; while further west on the shores of Lough Conn another distinct erenagh family was located.  For the name in Ulster as an indgeous sept see Lynn.

Flinn.  A frequent variant of Flynn.

(O) Lynn.  Ó Fhloinn, now usually made Ó Loinn.  This is the northern form of Ó Floinn (Flynn) and is the name of a sept located near Lough Neagh.  County Antrim.