How can I become an Irish citizen?

There are two main routes. Naturalisation is for residents: you generally need five years of reckonable residence in the last nine, including one continuous year immediately before applying, plus good character. Reckonable residence is mainly time on Stamp 1 (employment-permit work), Stamp 4 or Stamp 5 — student and graduate time on Stamp 2 or Stamp 1G does not count. Separately, Ireland has a generous citizenship-by-descent route: a person with an Irish-born parent is usually a citizen automatically, and a person with an Irish-born grandparent can become a citizen by registering in the Foreign Births Register (run by the Department of Foreign Affairs), with no need to live in Ireland. Ireland permits dual citizenship.