Colgan
An Irish surname linked in early sources to the word for a sword, suggesting an ancestor known as a swordsman or warrior.
The #8,965 most common surname in the United States (2010 Census) — about 1 in every 84,565 Americans shares it.
Etymology
The name is usually treated as Irish in origin. A source cited in the historical literature connects it with Irish colg, meaning "sword," so the surname would originally have functioned as a nickname or descriptive byname for a swordsman. The Irish forms in Woulfe also show it as an anglicized surname from an older Gaelic form beginning with O'-, meaning "descendant of."
History
Colgan is an established Irish surname, especially associated with Gaelic families in Ireland. Historical references place a Clan Colgan in County King’s (now Offaly) and nearby areas, showing that it belonged to an older Irish sept rather than being a recent imported name. It later spread with Irish migration and appears in modern records outside Ireland, including the United States.
Origin
Regions
Variant spellings
Fun fact
The surname appears in older genealogical and place-based references to a Clan Colgan in the Irish midlands.
From the historical record
“O'lIENNESY. The O'Hennesys were chiefs of Clan-Colgan in King's County, and of the territory now called the barony of Moygoish, co. Westmeath. O'lilFFERNAN. This sept possessed a territory about Corofin, co. Clare, called”
— Patronymica Britannica: a dictionary of the family names of the United Kingdom