Mackenna is a variant of McKenna, from a Gaelic surname meaning son of Cionaodh or born of fire.
Mackenna derives from the Irish and Scottish Gaelic surname Mac Cionnaoth or Mac Kennagh — 'son of Cionnaoth,' a personal name of uncertain etymology, possibly related to 'cin' (fire) or 'kenneth' as anglicized. The MacKenna clan was a notable family in Ulster, Ireland, particularly in County Monaghan, where they held territory and influence in the medieval period. As a surname it spread through Irish diaspora communities to Scotland, North America, and Australia, carrying with it the characteristic 'Mac-' prefix that signals Gaelic patrilineal descent.
The shift from surname to given name follows a well-established English-language pattern — think McKenzie, Madison, or Mackenzie — where strong clan surnames acquire new life as first names, particularly for girls in the late 20th century. Mackenna gained traction in the United States and Canada from the 1990s onward, riding the wave of 'Mac-' and 'Mc-' names that felt simultaneously traditional and fresh. The double-n spelling distinguishes it from Mackena or McKenna, giving it a slightly more substantial visual presence.
Today Mackenna is firmly established as a feminine given name in North America, popular among families with Irish or Scottish heritage and among those who simply love its warm, grounded sound. It sits at an interesting cultural moment: a name old enough to carry genuine genealogical depth, yet new enough as a first name to feel like a contemporary choice. It conveys a sense of heritage without heaviness, and it nicknames naturally to Mac, Kenna, or Kenny depending on the family's preference.