Mahon, Mohan, ó Mócháin
Sometimes an abbreviation of MacMahon (above). Also an anglicisation of ó Mocháin; descendant of Mochán (a pet form of some name commencing with Moch-, early) of which there were two septs in Connacht. A sept of the Cinel Ianna, in the diocese of Kilmacduagh in Galway. An ecclesiastical sept a branch of the Ui Fiachrach in Sligo, who were erenaghs of Killaraght, in the barony of Coolavin, and keepers of the cross of St. Attracta In 1890 Mahon was principally found in Dublin and Galway, and the estimated number of bearers was 3,900.