Woulfe describes MacConnon (Mac Canann in Irish) as rare and scattered. It is not very rare, being quite numerous in its homeland, viz Oriel, outside which it is seldom found. He does not mention MacCannon at all, though this name is still extant, and as it appears in nineteenth century birth registrations in the same parts of the country as MacConnon the two names may be regarded as synonymous. MacCannon is also found occasionally in Co. Donegal as an erroneous synonym of O'Cannon (see Irish Families p. 73). The sept of MacConnon was located originally in the Clones area, but in the eleventh century they moved southwards to south Monaghan where, with the adjacent Co. Louth, they are mainly found today. In 1659the “census” of that date records them as numerous in the part of Co. Meath nearest to Co. Louth. In Co. Louth some families of MacConnon have changed their name to MacConnell, an example of the not uncommon process whereby comparatively rare names become absorbed in better known ones of a somewhat similar sound. According to Woulfe the same thing happened in the case of MacCannon and the well known name MacCann. There are some families of MacCannon in Dublin now—the metropolitan area always contains names belonging to all the four provinces-and have long been there: George and William MacCannon were well known tailors who carried on their business in Dublin between 1730 and 1760. John MacCannon was Sheriff of Co. Monaghan during the brief Catholic regime under James II.

Contracted from Mac Cannanain, ‘Cannanan’s Son', (ceann-fhionn, 'white head').

‘Canannan, son of Ceallach, Tanist of Ui Ceinnsealaigh', a.d. 950.

‘From the family of O’Cannanain, of Tirconnell, Letter- KENNY, in Donegal, received its name, which is a shortened form of Letter-Cannanan, the O’Cannanan's hill-slope.’