Passengers arriving into Dublin Airport from all countries will now need to produce a negative COVID test from Sunday.
Those arriving into the country must produce a negative PCR test that was taken within the 72 hours before travel.
If they don't produce this test at the border, they risk a fine of €2,500 or six months jail time.
The same restrictions will apply at all Irish airports.
Rapid antigen tests will not be accepted, and the test must be carried out by a lab.
The rule had previously only been applied to passengers arriving from the UK or South Africa, but will now apply for all passengers.
UK and SA arrival will still have to restrict movements for 14 days, while EU rules will still apply for passengers coming from European countries upon arrival under the traffic light system.
Arrivals from red countries will have to restrict movements for five days on arrival even with a negative result, while orange and green arrivals won't once they have a negative PCR test.
