Two Irelands, Two Borders
If you're planning to visit Ireland, including Northern Ireland, you will be crossing two international borders, with two different rules.
Republic of Ireland
Tourists can enter the country visa-free for stays up to 90 days.
If you are not travelling to Northern Ireland then there are no other requirements.
Though not currently implemented, the European Union (and therefore Ireland) will require the ETIAS document later in 2025 or 2026 .
Northern Ireland
Northern Ireland is part of the United Kingdom and has different travel requirements from the Republic of Ireland.
Tourist visa: not required for stays of up to 6 months
Starting in January 2025, all travellers travelling to or transiting (connecting) through the UK must apply for an Electronic Travel Authorization (ETA).
You must travel on the passport used for your ETA application.
Northern Ireland is a member of the European Union, but it’s not part of the Schengen area. You must have a valid passport to travel between Ireland and other European countries.
Passport
You must have a valid passport to enter the Republic of Ireland or Northern Ireland. Or anywhere, really.