McDonough
An Irish surname meaning “son of Donnchadh,” though older writers sometimes linked it to the name Donagh or Donnough.
The #1,655 most common surname in the United States (2010 Census) — about 1 in every 14,202 Americans shares it.
Etymology
McDonough is an Anglicized Irish surname built on Mac, meaning “son of,” plus a personal name usually related to Donnchadh, the Gaelic source of Donogh/Donough. In that sense, the name is patronymic: it originally identified a person as the son of someone bearing that forename. Older sources sometimes treated it as a variant spelling or form of MacDonogh, MacDonagh, or McDonnell-related names, so the exact underlying personal name can vary by family line.
History
The surname is strongly associated with Ireland and later Irish diaspora communities, especially in English-language records where spellings shifted freely between Mac- and Mc- forms. Historical indexes and older onomastic works often place McDonough alongside Macdonough and McDonogh as spelling variants or near-variants, reflecting the fluid spelling practices of the 18th and 19th centuries. In the United States it became established through immigration and now appears in several regional concentrations.
Origin
Regions
Variant spellings
Fun fact
The spelling McDonough is one of several anglicized forms that can all appear in old records for closely related Irish patronymic surnames.
From the historical record
“MacDonough, MacDorchy, . MacDougall, . MacDowell, . MacDiivan, . MacEgan,”
— Special Report on Surnames in Ireland (numerical strength, derivation, distribution)