Passengers arriving into the Republic of Ireland will have to provide a negative Covid-19 test before departure from 16 January.
The test will have to be taken within the previous 72 hours.
Negative tests prior to arrival are already a requirement for passengers travelling from Great Britain and South Africa.
Travellers from Great Britain and South Africa must also restrict their movements for 14 days after arrival.
This applies even if a second test is taken upon arrival into Ireland.
Those arriving from countries on the green and orange lists of the European Union's traffic light system will not be required to restrict their movements after arriving in Ireland, however will be required to adhere to local restrictions in place.
Passengers arriving from countries on the red and grey lists, and places outside of Europe, must restrict their movements for 14 days.
However, if a negative test result is provided within five days of arrival to Ireland the rule can be lifted.
The Irish government said checks will be carried out at Dublin Airport by the Border Management Unit, with the Irish police force carrying out checks at other points of entry.
Exemptions apply to children under six years of age, as well as for other groups including international transport workers and garda (Irish police) members in the course of their duties.