This is a study into the DNA of the surname O’Shaughnessy, with all variant spellings. It is intended to provide a tool to assist in determining approximately how far back we must go to find a common O’Shaughnessy ancestor. This is a promising new field for genealogical research.  A minimum of the Y37-Marker test is recommended. Click the button on the left to join.

The name O’Shaughnessy started to be used in Ireland in the 1100’s A.D. as a FIRST name.  It comes from an O’Shaughnessy ancestor named Seachnasaigh (pronounced “Shock nahsook”).  Today, over 200 spellings of the surname have been found.

In the 1200’s, the O’Shaughnessy Clan settled in a fertile valley in the southwestern part of Ireland between the Aughty mountains to the east and Burren Hills to the west.  This area became known as CinelAodh, and is today in Counties Clare and Galway, The most senior part of the clan lived in Gort-inse-Guaire, now the modern town of Gort, Galway.

In the 1700’s members of the clan migrated south and southeast to West Limerick and North Cork,where many settled as farmers and millers. During the Famine years many emigrated to the USA, Canada, Australia and England.

The O’Shaughnessy Society holds a clan gathering every two years in Gort, Galway.  For information contact our project administrators or visit our website and our Facebook page.