McCullough
A Gaelic surname usually explained as “son of Culla/Cullough,” with some older writers linking it to a word for a boar or a brave man.
The #755 most common surname in the United States (2010 Census) — about 1 in every 6,734 Americans shares it.
Etymology
McCullough is a Gaelic-style surname built from Mac, meaning “son of,” plus a personal name or nickname such as Cullough/Culla. One traditional explanation treats the second element as Gaelic cuttach, meaning “boar,” used figuratively for a bold or fierce man. Some older Scottish writing also suggests a different possibility, connecting it with MacLulach or a form meaning “little calf,” but that derivation is less secure.
History
The name is found in both Ireland and Scotland, and its spelling has shifted over time into forms such as MacCullagh, MacCulloch, and MacColl. In modern usage McCullough is especially common in Ulster-descended families and across the English-speaking world. Because Gaelic names were often anglicized in several different ways, the surname now covers more than one historical spelling tradition.
Origin
Regions
Variant spellings
Fun fact
The same surname line can appear in several closely related spellings, which is why McCullough families often find older records under MacCullagh or MacCulloch.
From the historical record
“bold, generous ; also a term of endearment McCULLOUGH. The son of Cullough. Cuttach, Gaelic, a boar, figuratively, a brave man. McDHOIL or McDOWELL. (Gaelic.) The son of Dowell or Dougall, the dark stranger. From dhu, black, and gall, a native of the low country of Scotland ; any one ignorant of the Gaelic language…”
— An Etymological Dictionary of Family and Christian Names