Quick answer
If one of your grandparents was born on the island of Ireland — including Northern Ireland — and you were born abroad, you can become an Irish citizen by registering on the Foreign Births Register. You’ll need original civil records linking you, your parent and your grandparent. It doesn’t matter whether your parents ever held Irish passports.
The basic rule
Anyone born outside Ireland with a grandparent born on the island of Ireland can apply to the Foreign Births Register. Northern Ireland counts in exactly the same way as the Republic, and the Department of Foreign Affairs confirms your parents don’t need to have held Irish passports.
If your parent — your grandparent’s child — was also born on the island of Ireland, you don’t need the register at all: you’re already an Irish citizen and can apply for a passport directly.
What about great-grandparents?
A great-grandparent only helps if your parent had already been entered on the Foreign Births Register before you were born. Then you apply through your parent, not your great-grandparent. If your parent registered after your birth, you can’t claim through them.
Beyond that, applications based on Irish descent or associations are a separate route decided at the discretion of the Minister for Justice — see Citizens Information (opens in a new tab).
What you need to prove
Your application has to show an unbroken paper trail across three generations. For an adult applicant, that means original civil records for each person:
| Who | What to send |
|---|---|
| You | Civil birth certificate showing your parents, a certified copy of your photo ID, two proofs of address, four passport photos, and a marriage or change-of-name document if your name has changed |
| Your parent | Civil birth certificate, a marriage or change-of-name document if applicable, and a certified copy of their photo ID — or their death certificate |
| Your grandparent | Irish civil birth certificate, a marriage or change-of-name document if applicable, and a certified copy of their photo ID — or their death certificate |
The documents checklist turns this into a list you can tick off and print.
Finding your grandparent’s Irish records
Irish civil registration of births began in 1864. Search the free index for your grandparent’s birth with Find Irish documents — the mother’s maiden name and the registrar’s district narrow common names quickly — then order the official full certificate:
- Born in the Republic of Ireland, or in Northern Ireland before 1922: order from the HSE civil registration service (opens in a new tab) for €20 plus postage.
- Born in Northern Ireland: order a long birth certificate from GRONI (opens in a new tab) for £15.
Born before 1864? There’s no civil birth certificate, and the Department of Foreign Affairs accepts your grandparent’s baptismal certificate instead.
After you’re registered
You’re an Irish citizen from the date you’re entered on the register, and you can then apply for an Irish passport with your Foreign Birth Registration certificate. Any children you have after that date can register through you. Registration takes about 12 months — the step-by-step guide covers the process.
Sources
Checked against these official pages on . Requirements can change — confirm them before you apply.