Your Irish Last Name Can Provide Important Genealogical Clues

Your Irish last name can tell you far more than only that your ancestors were from Ireland. It can actually be the key you need to pinpoint the exact area in Ireland where your ancestors lived. Because many Irish families stayed in the same general location for generations, it’s not unusual for a certain surname to only be seen within a radius of a few square miles for hundreds of years. Even when surnames spread out somewhat in Irish genealogical research, they still often stay within one particular county. If you know the area in Ireland to which your surname was common, you can often break through some long-standing genealogical brick walls.

There are several databases online that provide geographical links to many an Irish last name. One of the best-organized of such databases is found at However, this website only catalogues the most common Irish surnames by location. More obscure or less common names may not be included. If this is the case for you, doing a Google search for your surname and including the phrase “Irish county” in your search terms should help you find the geographical information you’re looking for. There are also a wide variety of Irish genealogy message boards available to help you track down your surname’s county of origin.

One more important thing to remember about Irish surnames is that the name itself can give you important clues as to the history of the family. For example, surnames with O’ in front of them (such as O’Malley and O’Connor) mean “grandson of.” So, O’Malley would literally mean “grandson of Malley” and O’Connor would mean “grandson of Connor.”  Surnames with “Mc” in front of them mean “son of.” Knowing this information, combined with being aware of the county of origin of your ancestors, can help you locate some of your most ancient ancestors and give you the clues you need to trace your Irish family into the present.


  1. Lisa Rust May 20, 2010
  2. Stephanie April 28, 2009

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