McGaughey is an Irish surname of Gaelic origin, stemming from the original patronymic phrase Mac Eachaidh, which translates to "son of Eachaidh". The personal name Eachaidh derives from the Gaelic word each meaning "horse", so the surname may be understood as "son of the horseman".
In its earliest usage the name served as a descriptor of lineage rather than a settled family name; it identified a person as a descendant of an ancestor distinguished by horsemanship or by a particular association with horses.
The Mac(e)Caughey clan is historically linked with the Ulster region of Ireland. Records first mention the name in County Tyrone dated 1685, and several early documents cite individuals such as John McGaihy (1719), Elizabeth McGahy (1711), and Jane McGahey (1846). A christening record from 1709 names a witness as Jas. M'Gachy in Carmoney, County Antrim, during the reign of Queen Anne.
Because the original Gaelic terms were rendered into English, the surname has accumulated many orthographic variants. These include McGaughey, McGaughie, McGauhy, McGahey, McGahy, McGAffey, Megahey, Gaffey, MacCaughey, McGeoghegan, and MacGeoghegan. Despite the varied spellings, all trace back to the same Gaelic root.
The prevalence of the name is greatest in Northern Ireland, particularly around Ulster, but migration has spread bearers of the surname to the United States and other English‑speaking countries. The name remains uncommon in the broader Irish population, yet its historical depth is evident in the recorded attestations across several centuries.
Thus, the surname McGaughey encapsulates a lineage that can be read as a testament to Gaelic patronymic tradition and the cultural importance of horse riding within early Irish society. Every documented form, however altered, continues to acknowledge its origin in the name Mac Eachaidh and its meaning that reflects the affinity of its ancestors for the horse.