Saint Carthage the Elder (or Carthach) was an Irish bishop and abbot in the sixth century. His feast day is 5 March.

The saint is mainly known as a disciple and successor of Ciaran of Saighir (the Elder) and the tutor and fosterer of his greater namesake, Saint Carthage of Lismore (also known as Saint Mochuda).^[1]

Carthage was of the Eóganacht Chaisil and son, or, more probably, grandson of Óengus mac Nad Froích whom Saint Patrick baptized. He was sent by St. Ciaran upon a penitential pilgrimage, when he spent seven years abroad, visiting Gaul and Rome. On completion of his canonical penance, Carthage was reinstated as a member of the religious brotherhood of Saighir. Afterwards he founded the monastery of Druim Fertain in Carberry and another monastery in the upper island of Lough Sheelin, County Meath.^[2]

In the barony of Clanmaurice is a townland called Monument on which are some scant remains of an ancient church called Cill Cartaig (Carthage's Church).

There is a short paragraph about St. Cartha in The Martyrology of Donegal: a Calendar of the Saints of Ireland (1864) by James Michael O'Clery, page 65:

Carthach, Bishop, alumnus of Ciaran of Saighir. One of his places was Druim-fertain, and in Cairbre Ua Ciardha is Druim-fertain; and to him belongs Inish Uachtair in Loch Sileann, and Cill Charthaigh in Tir Boghaine in Cinel Conaill. He was son of Aenghus, son of Nadfraech king of Munster, &c.

Cill Charthaigh is Kilcar.