As of today 28 September 2020, Ireland's Green List of countries from which people can enter (or re-enter) Ireland without completing a Passenger Locator Form and self-isolating for 14 days is down to just:
Ireland's Department of Foreign Affairs and Trade continues to advise against non-essential travel to destinations outside Ireland (including the UK but not Northern Ireland) other than to the Green List countries.
On 15 September the Government of Ireland announced a 5-level plan for Living with COVID-19 to be effective at least until the spring of 2021. Different levels of restrictions will be imposed on a county-by-county basis depending on the level of COVID-19 infections.
Currently, Dublin (City and County) is at Level 3 until 9 October and County Donegal is at Level 3 until 16 October. Level 3 carries additional levels of restrictions on nonessential travel.
Clearly, 2020 is going to be a Lost Year for Tourism Ireland.