All passengers arriving into Ireland will have to provide a negative Covid-19 test prior to departure from this Saturday, 16 January.
The negative test must be taken within 72 hours prior to arrival in Ireland.
Arrivals from Britain and South Africa had already been required to provide a negative test, under measures that were announced last week.
People arriving from Britain and South Africa will still be required to self-isolate for 14 days, even if they take a second test after arrival.
Arrivals from red and grey list countries, as defined by the EU traffic light system, and all other locations outside of Europe must restrict their movements for 14 days.
However, this may be lifted if the person receives a negative/not detected result to a test taken no less than five days after arriving in Ireland.
People arriving from green and orange list countries will not be required to restrict their movements on arrival, but must adhere to the local public health guidance.
In a statement, the Government said checks will be made by the Border Management Unit at Dublin Airport and by An Garda Síochána at other points of entry.
There will be exemptions from the requirement for certain groups, including international transport workers and garda members in the course of their duties.
Children under six will also be exempt.
Meanwhile people travelling from Ireland will now face quarantine in Switzerland, officials said, following World Health Organization warnings of a "massive increase" in cases.
Arrivals from Ireland joined those from countries including the United States, the UK, South Africa and Sweden in having to undergo ten days of quarantine.
The new rules came after WHO emergencies director Michael Ryan drew attention to the situation in Ireland.
He told a press conference in Geneva yesterday that the country had "done extremely well" in two surges of disease but had since suffered "one of the most acute increases in disease incidence of any country".
Ireland had officially registered just over 93,000 cases on 1 January but that figure had jumped to more than 150,000 by yesterday.
Dr Ryan said the rise was due to increased social mixing rather than the emergence of a new, apparently much more contagious strain of the virus first detected in England.
He said Ireland had taken "immediate action" over the last fortnight and the positivity rate was now starting to drop.
The Netherlands, Denmark and the Czech Republic are due to join the Swiss quarantine list on Friday.
Failing to comply with the quarantine requirement can result in a fine of up to €9,250.
