The European-wide traffic light travel system to deal with Covid-19 comes into effect from this morning, with the majority of areas in red.
Greenland is the only area within the green categorisation, while visitors to Ireland from parts of Greece, Norway and Finland which are in the orange list, can skip quarantine if they test negative for the virus three days before landing here.
Every other area is red, meaning they must complete 14-days of isolation, which can only be stopped if there's a negative test five days after coming into a country.
The estimated national 14-day incidence rate of Covid-19 has fallen to its lowest point in almost a month.
It now stands at 175 cases per 100,000 for the first time since October 12th.
Three counties now have a total of less than 100.
It comes as 542 new cases of the virus were reported in Ireland yesterday - along with two additional deaths.