Four Tips for Researching Irish Ancestors

By Sharon DeBartolo Carmack

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Think of these four tips as your leaves of a lucky four-leaf clover—will help make your Irish ancestor search more successful.

1. Know the place

Although online databases and digitized records have made Irish research quicker and easier, it’s helpful to know from where in Ireland your ancestors came before you begin searching them. A county name is good, but if you can discover the name of the townland—the smallest geographic locality in Ireland, similar to an American neighborhood—that’s even better.

2. Thoroughly research American sources

Start with what you know and move backward in time is a basic rule of genealogy. Make sure you research every possible record in the United States for your immigrant ancestor, as well as his family members and associates. Records of those relatives and associates might give you that townland name. And when you search Irish records, those details from your ancestor’s and other folks’ records can be invaluable. There are thousands of Mary Kellys, Joseph O’Briens and Michael Donovans. Knowing as much as you can about your ancestor from American records can help you make a positive ID in Ireland.


3. Tap living relatives

Family members might have clues to where your relatives came from in Ireland, as well as other genealogical leads. Don’t overlook childless couples or unmarried relatives. In Irish families, almost as many people stayed single as married, and these maiden aunts and bachelor uncles—and even relatives who became nuns and priests—might be the genealogical gatekeepers.

4. Be aware of name variants

Sometimes the Irish, or US clerks who recorded their names, dropped an O’, Mc or Mac surname prefix. You might find your ancestor listed in records variously as O’Riordan and Riordan. When you’re searching records and indexes, look for the surname both with the prefix and without it.

Also check for alternate spellings in an Irish surname dictionary. McGarr in America could be McGirr in Irish records. The surname MacGanly could also be Gantley, but the Gaelic spelling is Mag Sheanlaoich, so a variant English form is Shanly. And Knockton could be Naughten.


Two helpful books to help you sort out Irish surnames are Edward MacLysaght’s The Surnames of Ireland (Irish Academic Press) and Robert E. Matheson’s Special Report on Surnames in Ireland (free on Internet Archive or with Varieties and Synonymes of Surnames and Christian Names in Ireland from Genealogical Publishing Co.).

A version of this article originally appeared in the March/April 2012 issue of Family Tree Magazine. is a participant in the Amazon Associates Program, an affiliate advertising program. It provides a means for this site to earn advertising fees, by advertising and linking to Amazon and affiliated website.