This name is quite numerous and should have been included in More Irish Families on that account.

In 1865 58 births were registered for Marren (24) and Marron (34); nearly all the Marrens were in Co. Sligo and most of the Marrons were in the Carrickmacross area of Co. Monaghan. In 1890 there were 31, with the same distinction between Marren and Marron, but the latter were then much more numerous.

In the Co. Monaghan hearth money rolls (1663 and 1655) we find O'Maran, O'Marran and O'Meran, while in the “census” of 1659 O'Merran was a “principal Irish name” around Carrickfergus, Co. Antrim.

O'Meran appears too in a north Mayo Fiant. In Matheson's list of modern synonyms Mearn is recorded with Marron in Ballymena, Co. Antrim, but this Mearn may be the Scottish Mearns of Kirkcudbrightshire. The Gaelic form of O'Marron is clearly Ó Mearáin. I can find no positive evidence indicating the early history of the sept; it seems probably that there were in fact two septs so called, one in Oriel and the other smaller one in the Ui Fiachra country—but there is no mention of the latter in The Tribes and Customs of Hy Fiachra.