Cooley
Usually an Anglicized Irish surname from Ó Cuile / Mac Giolla Cuile, though in some English families it was also treated as a spelling of Cowley.
The #1,054 most common surname in the United States (2010 Census) — about 1 in every 9,291 Americans shares it.
Etymology
In Irish usage, Cooley is generally an Anglicized form of surnames built on cuile or Cuile, as shown in older surname collections that link it with forms such as Ó Cuile and Mac Giolla Cuile. The underlying Irish element is not fully explained in the excerpted sources, but the surname is clearly part of the Gaelic naming tradition and was later rendered in English spelling as Cooley. In English records, however, Cooley was also sometimes used as a variant spelling of Cowley, so the name can have more than one historical origin depending on the family.
History
The surname appears in English and Irish records with overlapping spellings, which has made its history a little tangled. Lower explicitly treated Cooley as a corruption or variant of Cowley in some English lineages, while Woulfe connects Cooley to Irish forms such as Ó Cuile and Mac Giolla Cuile. As a result, modern bearers of the name may descend from either an English Cowley-like line or an Irish Gaelic surname that was later Anglicized as Cooley.
Origin
Regions
Variant spellings
Fun fact
Lower noted that even the ancestors of the Duke of Wellington used several spellings, including Colley, Cowley, and Cooley, before the family settled on Wellesley.
From the historical record
“Y being an unnecessary addition. COOLEY. Probably a corruption of Cowley. The ancestors of the Duke of Wellington, prior to their assumption of the name of Wesley or Wellesley, wrote their name indifferently Colley, Cowley, and Cooley. Times, 15 Sept., 1S52. So Cooper was anciently Cowper. COOLING. A parish in…”
— Patronymica Britannica: a dictionary of the family names of the United Kingdom