Finding your Irish ancestry can be tricky and a daunting task not least because a large portion of Ireland’s 19th-century census records were destroyed in 1922 when a fire broke out at the Public Record Office of Ireland.
So how to go about to find your Irish ancestry.

Start with family
Most people would think that the most obvious place to start would be online but we suggest that start by talking to your family. You can spend days going through records to find a surname which might be known by someone in your family. Start with your parents and grandparents, move on to your extended family and collect as much information as you can.
Often a member in your family had the same desire to find their ancestry and could have already done some or all of the work that you are starting now.
Go Online
Online resources
Despite the fact that a large number of records were destroyed in 1922 there are sources that survived and these are available online and are free to access. These are censuses, tax surveys, civil records and church registers.
We suggest starting with National Archives of Ireland census website (census.nationalarchives.ie).
You will find a lot of information from these and can then move on to other resources.
It is fortunate for the individual researcher that most Irish records are free online. One of the main reasons is that there are more than ten times more people in the United States that claim Irish descent than there are in Ireland, this is something that is unique to Ireland.
In the 1990s,it became government policy to make as many records as possible freely available online.
With a few Google searches most of these records could be found easily.
Pay an expert to find your heritage
The option of paying someone else to find your heritage is always open to those spending the money and a number of online companies provide this service.
Finding your Irish roots can be satisfying and is something that lots of people are very proud of, not least of them, American President Joe Biden, who can trace his Irish roots back to both the Blewitts from Co Mayo and the Finnegans from Co Louth.
One of the most exciting and satisfying things to do after you have more information is to visit Ireland and go to the places where your ancestors lived. All of us have a desire to know where we come from and an Irish heritage is definitely something you can be very proud of.
The Counties of Ireland
As we have stated above Joe Biden can trace his roots back to county Mayo and county Louth. So what are these counties of Ireland?
The counties are historical administrative divisions which began as Norman structures and political control came to be established on county level over time.
Historically, Ireland had 4 Provinces – Ulster, Connaught, Leinster and Munster and rugby fans will recognise these provinces by their rugby teams.
These provinces are now divided into counties as follows
Ulster
Antrim, Armagh, Cavan, (London)Derry, Donegal, Down, Fermanagh, Monaghan, Tyrone.
Connaught
Galway, Leitrim, Mayo, Roscommon, Sligo.
Leinster
Carlow, Dublin, Kildare, Kilkenny, Laois/Leix (aka Queens), Longford, Louth, Meath, Offaly (aka Kings), Westmeath, Wexford, Wicklow.
Munster
Clare, Cork, Kerry, Limerick, Tipperary, Waterford.
Famous people with Irish roots
It is said that at least 23 American Presidents have Irish roots but there are some other famous names that might surprise you.
Let’s start with the current US President – Joe Biden
President Biden’s great-great grandfather on his mother’s side, Patrick Blewitt was born in Ballina in county Mayo in 1832 and immigrated into the USA in 1850.
James Finnegan, Biden’s great-grandfather on his father’s side was born in county Louth and emigrated from Ireland to America in the late 1840s.
An interesting fact is that Rob and Dave Kearney, Ireland rugby internationals, father is supposed to be a fifth cousin of President Joe Biden.
Tom Cruise
Tom Cruise is an A-list Hollywood actor and known for many movies such as the “Mission Impossible” franchise, “Jerry Maguire” and Born on the Fourth of July’
Cruise traveled to Ireland and traced his heritage back to Dublin, where he was given an honorary Certificate of Irishness, an official recognition by the Irish Government.
Robert De Niro
Robert De Niro is one of the most acclaimed actors in Hollywood, known for his roles in The Godfather , The Deer Hunter and many other movies. De Niro has won a number of awards including 2 Oscars and many see him as the greatest actor of all time. De Niro’s Irish roots are well documented.
George Clooney
George Clooney is also a well known star winning 3 Golden Globes and 2 Oscars
George’s paternal great-great-grandfather, Nicholas Clooney, was born in Windgap, Ireland in 1829, and his great-great-grandmother, Bridget Byron, was born in Limerick, Ireland in 1835.
Jack Nicholson
Jack Nicholson’s has been nominated for the Academy Award 12 times, winning 3 Oscars. His movies are too numerous to mention but includes “One flew over the cuckoo’s nest” and “The Departed”
Jack’s maternal great-grandmother, Ella Nicholson (born Lynch), was born in 1867 in Cork, Ireland.
So, let’s grab a pint of Guinness and start searching for your Irish roots.
By the way, here is a list of the top 10 places to visit in Ireland.
Secure Your Dream Irish Experience Before It’s Gone!
Planning a trip to Ireland? Don’t let sold-out tours or packed attractions spoil your journey. Iconic experiences like visiting the Cliffs of Moher, exploring the Rock of Cashel, or enjoying a guided walk through Ireland’s ancient past often sell out quickly—especially during peak travel seasons.

Booking in advance guarantees your place and ensures you can fully immerse yourself in the rich culture and breathtaking scenery without stress or disappointment. You’ll also free up time to explore Ireland’s hidden gems and savour those authentic moments that make your trip truly special.
Make the most of your journey—start planning today and secure those must-do experiences before they’re gone!