From today, anyone arriving to an airport or sea port in the Republic of Ireland will need proof of a negative Covid-19 test.
The tests must be professionally taken, as the Government will not accept a self-test.
The new rules are that people arriving into this country that have proof of vaccination or recovery from Covid can either show a negative PCR test, taken with 72 hours of arriving here, or a negative antigen test taken within 48 hours of arrival.
Passengers to Ireland who arrive without a negative test result are required to home quarantine and take a PCR test within 36 hours of arrival.
The Government says these measures are temporary and will be kept under constant review.
Meanwhile, Irish passengers will not require a negative Covid-19 test before travelling to the UK, after new rules were announced by the British government yesterday evening.
From Tuesday, all inbound passengers to the UK, from outside the Common Travel Area, will be required to produce a negative antigen or PCR test result.
The British government said it was intended to be a temporary measure following new data showing an increase in the number of cases of the new Omicron variant linked to foreign travel.