Landed Estates
NUI Galway

O'Brien (Fairfield)

Mary Casteleyn's article in ''The Irish Genealogist'' gives a detailed history of this family. Besides their land in county Galway the O'Briens also had land in county Roscommon at Kilmore and Clonboy or Clyboy, parish of Athleague, barony of Athlone. In 1850 James Scott Molloy, assignee of Thomas O'Brien, advertised the sale of the O'Brien estate at Fairfield and Kilmore, amounting to 1439 acres, in the Encumbered Estates' Court. At the time of Griffith's Valuation Kilmore was in the possession of Edward Corcoran and John Sadlier. Dillon O'Brien, a younger brother of Thomas, emigrated to Minnesota, where he became a prominent layman in the Catholic church in America and an author. Marie Adelaide O'Brien, grandmother of Florimond de Basterot was a member of this family. The O'Briens were also related to the O'Connors of Corristoona and Milltown, the Dillons of Dillon's Grove and the Comerfords.


Name Townland Civil Parish PLU DED Barony County Map Ref
Fairfield (Kilgerrill) Fairfield Kilgerrill Ballinasloe Killure 2 Clonmacnowen Galway OSI Ref: M781359
OS Sheet: 74
Discovery map: 47
Kilmore Kilmore Athleague Roscommon Athleague East 87 Athlone Roscommon OSI Ref: M853 560
OS Sheet: 41
Discovery map: 40

Archival sources

  • Encumbered Estates' Court Rentals (O'Brien). Molloy, 4 June & 17 Dec 1850, Vol I & 4, MRGS 39/001 & 39/002 (Microfilm copy at NUIG). ; National Archives of Ireland

Contemporary printed sources

Modern printed sources

  • ''The Irish Genealogist'': CASTELEYN, Mary. The O'Briens of Fairfield, Co Galway: the O'Brien relations of Florimond, Comte de Basterot''. XI No. 3 (2004), 190-204