Darby
A surname most often taken from Derby, the English city and county—though in Ireland it can also reflect the Gaelic personal name Diarmuid.
The #1,921 most common surname in the United States (2010 Census) — about 1 in every 16,460 Americans shares it.
Etymology
In English use, Darby is generally a spelling variant of Derby, meaning someone who came from Derby in Derbyshire. The place-name Derby is traditionally linked to Old Norse elements meaning something like 'deer village' or 'deer settlement,' though the exact early form is complex. In Irish contexts, Darby can also be an anglicized form of Diarmuid, a traditional Gaelic personal name that later became associated with the nickname Darby.
History
The surname appears in English records in forms alongside Derby, with the spelling Darby becoming established as a variant pronunciation-and-spelling form in some regions. Bardsley and Lower both treat it as a corruption or variant of Derby, especially in northern English usage. In Ireland, however, Darby may also have developed independently as an anglicized personal-name surname from Diarmuid. The name is still found in both English and Irish family lines.
Origin
Regions
Variant spellings
Fun fact
The same surname form can point either to an English place-name origin or, in Irish families, to a completely different Gaelic personal name.
From the historical record
“DARBISHIRE. See Counties. DARBY. A corruption of Derby. So Darbishire from Derbyshire. D'ARCY. DARCEY. Under William the Conqueror, Norman de Adreci, or Areci, was a tenant in chief in Lincoln- shire, which was the principal seat of the family during many generations, whence the earl of Holderness. Collins'…”
— Patronymica Britannica: a dictionary of the family names of the United Kingdom