An Irish-born great-grandparent can lead to Irish citizenship, but not on their own. Whether it works for you comes down to one date: was your parent on the Foreign Births Register before you were born? If yes, you can register too. If no, the line stops with your parent, and registering them now won’t change that for you.
The short answer
- Your parent was registered before your birth (or before 1 July 1986): your parent was an Irish citizen when you were born, so you can apply to the Foreign Births Register and then for an Irish passport.
- Your parent registered after your birth, or never registered: you have no claim through that great-grandparent. The Department of Foreign Affairs puts it plainly: if a parent is not on the Foreign Births Register when the child is born, the child is not entitled to Irish citizenship.
Why each generation works differently
Follow the line down from the Irish-born great-grandparent:
- Your grandparent (child of the Irish-born great-grandparent) was an Irish citizen from birth. Under section 7 of the Irish Nationality and Citizenship Act 1956, a person is Irish from birth if either parent was an Irish citizen at the time, and a parent born on the island of Ireland passes this on automatically.
- Your parent had an Irish citizen parent who was born abroad. That kind of citizenship only passes on through the Foreign Births Register. Your parent could register because one of their grandparents (your great-grandparent) was born in Ireland.
- You can only register if your parent was already an Irish citizen when you were born. Since 1 July 1986, a person entered on the Foreign Births Register is Irish only from the date of registration, not from birth. So a parent registered after you were born was not Irish at your birth.
The 1986 exception
Before 1 July 1986, registration took effect from birth. The statute’s rule that citizenship starts only on the date of registration applies to people registered after that date. So if your parent was entered on the Foreign Births Register before 1 July 1986, they are treated as Irish from their own birth, and therefore at yours, even if you were born before they registered. A 1994 amendment also deals with some registrations that were in progress around 1986. If your family’s registration falls near that date, ask the Foreign Birth Registration office to confirm how it applies.
What you can still do if the line is broken
- Protect the next generation. If your parent can still register, doing so makes them an Irish citizen. It won’t reach you if you were already born, but it matters for any of your siblings born after the registration.
- Check every line, not just one. Another grandparent, or a parent born on the island of Ireland, may give a stronger claim than the great-grandparent you started with. See citizenship through grandparents.
- Naturalisation on the basis of Irish descent. Section 16 of the 1956 Act lets the Minister for Justice, at their absolute discretion, waive the normal naturalisation conditions for a person of Irish descent or Irish associations. It is not an entitlement, and there is no published process or timeline you can count on. Contact the Department of Justice’s immigration service before relying on it.
If your parent did register in time: the steps
- Gather your own documents: your original civil birth certificate showing your parents, any marriage or name-change certificate, a certified copy of your photo ID and two proofs of address.
- Gather your parent’s documents: their original civil birth certificate, marriage certificate if applicable, a certified copy of their photo ID (or their death certificate) and their original Foreign Birth Registration certificate.
- Apply online, then post the documents. The form and two of your four photos must be witnessed by someone from the DFA’s list of professions who knows you personally and isn’t a relative.
- Pay the fee: €278 for adults and €153 for under-18s (registration, certificate and postage, as listed by the DFA).
- Wait about 12 months. You can’t apply for an Irish passport until you are registered and hold your certificate.
The full process is in our Foreign Births Register guide, and the wider picture in the Irish citizenship by descent guide.
Frequently asked questions
Can I get an Irish passport through my great-grandparents?
Only if your parent was entered on the Foreign Births Register before you were born (or registered before 1 July 1986). In that case your parent was an Irish citizen when you were born, so you can register on the Foreign Births Register yourself and then apply for a passport. If your parent registered after your birth, or never registered, you have no claim through that great-grandparent.
My parent can still register. Will that help me?
It makes your parent an Irish citizen from the date of registration, but it does not reach back to you if you were already born. The Department of Foreign Affairs says that if an expectant parent is not on the Foreign Births Register when the child is born, the child is not entitled to Irish citizenship.
Is there another route for great-grandchildren?
Irish law lets the Minister for Justice waive the normal naturalisation conditions for a person of 'Irish descent or Irish associations' (section 16 of the 1956 Act). It is a discretionary power, not an entitlement, and there is no published process or timeline that great-grandchildren can count on. Ask the Department of Justice before relying on it.
Does a great-grandparent born in Northern Ireland count?
Yes. For citizenship by descent, a birth anywhere on the island of Ireland counts the same way, whether in the Republic or Northern Ireland.
How long does Foreign Births Register registration take?
The Department of Foreign Affairs currently states approximately 12 months for a complete application, processed in strict date order. Expectant parents should mark this clearly on their application.
Official sources
- Department of Foreign Affairs: Registering a foreign birth (eligibility, documents, fees, processing time)
- Irish Nationality and Citizenship Act 1956, revised (Law Reform Commission) (sections 7, 16 and 27)
Checked against these sources on 21 October 2026. Rules and fees change; confirm with the Department of Foreign Affairs before you apply.