Ancestral Counties in Ireland

By Kyle J. Betit Premium

Q. I’m tracing my grandfather, who’s from Ireland. I have his application and final paper for citizenship, with the year. What would be my next step if I have no idea what county in Ireland he came from?

A. In most cases, Irish surnames are relatively common. Unless you have a really uncommon surname that comes from only one or two counties in Ireland, you ‘ll need to determine a specific place of origin in Ireland from US records before you go searching in Irish records.

Naturalization papers can be a good source for this information, depending on the time period and locality. Remember, you’ll want to examine both the Declaration of Intention and the Petition for Naturalization. These two documents were usually filed years apart and could have been filed in different courts. They may contain significantly different information. Websites including, and have collections of naturalization records or indexes for various places and years; also see our tips for finding ancestors’ citizenship papers.

Records generated when the immigrant ancestor died also are good possibilities for finding a place of origin in Ireland: death certificates, cemetery registers, tombstones, church burial records, newspaper obituaries, funeral home records, funeral cards. It is also helpful to know the immigrant’s parents’ names, especially the mother’s maiden name.

You should be tracing not only your grandfather, but also other relatives who came over from Ireland, to see whether their records give the county of origin. This includes siblings and other relatives who may have settled in other countries abroad.

If your grandfather’s neighbors in census records show Ireland as a birthplace, it’s worth tracing those folks as well, as immigrants often traveled and settled together.
You can find a detailed discussion of Irish immigrant research in our digital book A Genealogist’s Guide to Discovering Your Irish Ancestors by Dwight A. Radford and Kyle J. Betit (Betterway).

Family Tree University’s Irish Research 101 course is designed to help you pinpoint your ancestor’s place of birth in Ireland. The downloadable Independent Study version of  the Irish Research 101 course is part of our Irish Genealogy Premium Collection, along with our Irish Genealogy Cheat Sheet, a video class on finding Irish Famine-era immigrants and other tools.

Learn more about what’s in the Irish Genealogy Premium Collection at Family Tree Shop.