Born in Ireland
To get an Irish passport, you must first become an Irish citizen. Fortunately, Americans can hold dual citizenship, as can Irish, so there’s no conflict there.
Let’s look at the scenarios that allow you to claim Irish citizenship.
Anyone born in Ireland before January 1, 2005 is an Irish citizen. After that date, it is not automatic, and the citizenship and residency history of both parents is taken into account.
Marriage to an Irish citizen
You are also entitled to Irish citizenship if you are married to an Irish citizen.
To claim citizenship by marriage, you must meet the following conditions: you must be married to an Irish citizen for at least three years; you must have had one year of “continuous residence” on the island of Ireland immediately before the date of your application; and finally, you must have been living on the island of Ireland for at least two of the four years before that year of continuous residence.
If you were born outside of Ireland and either your mother or father (or both) was an Irish citizen at the time of your birth, then you are entitled to Irish citizenship.