It is not possible to give a reasonably accurate estimate of the number of people living abroad who are entitled to Irish citizenship, as distinct from the number who actually are Irish citizens. Entitlement to citizenship under Irish law is generous by comparison with citizenship law in other countries. It includes people married to Irish citizens for at least three years and grandchildren, and in some cases great-grandchildren, of people born in Ireland. There is no way of knowing in advance whether people entitled to Irish citizenship through marriage or by descent will choose to exercise that entitlement.
Of the total of about 2.7 million passports issued by the passport offices in Ireland and by Irish embassies and consulates abroad in the past ten years and currently in circulation, we estimate about 700,000 were issued by Irish embassies and consulates abroad. About 430,000 were issued by the embassy in London and about 270,000 by other missions.
A rough estimate of the total number of Irish citizens abroad who were born in Ireland is 1.2 million.