You must have a valid passport to enter Ireland. U.S. citizens can enter visa-free for tourism or business stays of up to 90 days. There is no minimum passport validity requirement for U.S. citizens entering Ireland.
Do I need a Covid test to go to Ireland?
Travel restrictionsAll COVID-19 restrictions for travelling to Ireland have been lifted. You no longer need to complete a passenger locator form. You also no longer need proof of vaccination or recovery, or a COVID-19 test.