genealogies of the families
COURT COURTNEY (O)CURNEEN makes the suggestion that this name. Mac Cuairt Cuarta in Irish. is a corruption of Mac Mhuirchear. The latter, anglicized MacKurdy or MacCurdy, is a variant of Mac Muircheartaigh i.e. MacMurtry in Antrim, MacBrearty in Donegal and Murtagh in some places. MacCourt however, should be treated as a surname of independent origin. It belongs now, and has belonged as far back as records are available, to counties Louth and Armagh. In the Hearth Money Rolls of the latter county it is spelt MacQuorte. Father Ronan in his Irish Martyrs gives the anglicized form of Mac Cuarta (Co. Armagh as MacWorth. In Co. Cork this name has been curiously equated with Rothe, e.g. in a lease of 1584 to Ellis Rooth alias MacWoorthe (Tanner Letters. (p 519). The name has been made famous in the literary of Ireland by James MacCourt or Seamus Mac Curta (1647-1732) whose poems were collected and published by Rev. L. Murray. He was a friend of Turlough O'Carolan and has been described as "the greatest of the northern Gaelic poets". He was known as Courtney as well as MacCourt.
Courtney. however, usually of quite different origin from this, is a common name in several parts of Ireland. It is principally found in Kerry and adjoining areas, where it is the normal anglicized form of the Gaelic O Curnain, sometimes more properly called Cournane in English around Killarney and Tralee. It has been claimed that his family was abranch of the O'Curneens (O Cuirnin in Irish) who were poets and chroniclers to the O'Rourkes of Breffny. The Courtneys who are now to be found in north-east Ulster (sometimes under the form of MacCourtney) may possibly be descendants of this Breffny sept, but are more probably either MacCourts (the Irish name of the village of Cappagh, near Dungannon, is Ceapach Mhic Cuarta): or alternatively settlers from England: for it must not be forgotten that Courtney is a well known Norman name: one de Courtenai took part in the Anglo-Norman invasion under Henry II, and in 1383 Sir Philip de Courtney was the King's lieutenant in Ireland. The Earls of Devon, who owned 33,000 acres in Co. Limerick in 1878, were of this family.
Source: More Irish Families by Edward MacLysaght MA, D Litt, MRIA - Irish Academic Press 1996