The name Mernagh in Ireland is derived from the MacMurchadha Sept of County Wexford who originally anglicized their Gaelic name as MacMurrough. The Sept divided into a number of factions who in turn anglicized their names as Kavanagh, Kinsella, Hendrick and Mernagh.

Origin: Irish. First found in County Wexford and neighboring areas in Counties Carlow and Wicklow.

Spelling variations include: Mernagh, Merna, Merenagh and others.

Motto Translated: Peace and plenty.