In order to be eligible for Irish Citizenship, either:
– One of your grandparents must have been born in Ireland OR
– Your great grandparent was born in Ireland and your parent must have registered themselves on the foreign births register before you were born.
There is another route towards Irish Citizenship via ancestors beyond grandparents, but this process is up to the discretion of the Minister and is not guaranteed to succeed.
To find out more you can contact the DFA for any specific queries.