Do I need an ETA to travel just in Ireland? I'm a US citizen. I'm flying RT to Dublin
No, if you are staying in the Republic then you don't need one.
However, if you plan to go to Northern ireland you technically do need one. (Although there is an open border between ireland and Northern Ireland.)
thank you!
Frank, we are taking a tour that includes an enroute stop at the Ulster American Folk Park (between County Donegal and Dublin). I assumed that we would need an ETA for this stop and because we were crossing the Ireland/northern Ireland border twice, but I wasn't sure how strict this requirement was enforced for transits of this nature.
There is no "border" as such to cross as you will be within the common travel area and in many places the only way you know if you've crossed it is the speed limit signs change from KM to miles. It is a requirement to have at ETA in Norther Ireland, and I certainly wouldn't advise NOT getting one, but the chances of anyone checking this if you're visiting Ulster American Folk Park for the day are basically zero.
The point is not how strictly a law is enforced, but whether you are willing to comply with that law.
You need an ETA to travel to the UK https://www.gov.uk/eta?step-by-step-nav=e8254fb0-f2d9-45b1-bdc4-d17cbba11bef
Think of the border between Ireland and Northern Ireland like the border between US states. The only way you know you've crossed the "border" is by seeing the "Welcome to..." sign.
Why not just comply. For most people the process is quick, easy and inexpensive. You will have the advantage of being in the right.
If you are not traveling through the UK on your way to Eire no ETA is necessary. BTW - the last flight we took to Dublin changed planes at Heathrow. I’ve heard conflicting reports on whether an ETA is required if you stay airside.