Passengers flying to the US no longer need to complete a pre-departure Covid-19 test, under new regulations that came into effect at midnight EST (5am Irish time).
The US Centers for Disease Control and Prevention announced its decision on Friday and said it was "based on the science and data that this requirement is no longer necessary".
The Department of Foreign Affairs confirmed: "Passengers traveling to the United States from Ireland are no longer required to show a negative Covid-19 viral test or documentation of recovery from Covid-19 before they board their flight."
However, travellers must still present proof of vaccination - but a booster dose is not required. Children under 18 do not need to show proof of vaccination status.
The US accepts the EU Digital Covid Certificate as proof of vaccination.
The operator of Dublin Airport has said the change "does not materially impact the passenger journey" through the airport at this busy time of year.
US-bound passengers must also complete an ESTA (Electronic System for Travel Authorisation). The Department of Homeland Security recommends it be submitted at least 72 hours in advance of travel.
Once approved, it is valid for multiple entries into the US and generally for up to two years, or until your passport expires - whichever comes first.
In most cases, you must have a passport valid for at least six months after the date you enter the US.
However, Ireland has an agreement that allows citizens to enter the US on a current passport up to the actual date of expiration – so an Irish passport needs to be valid only for the duration of your stay.
Last month, the United States crossed the threshold of one million Covid deaths, with President Joe Biden acknowledging the "unrelenting" pain of bereaved families, and urging Americans to remain vigilant.
Many mask mandates across the United States have been lifted, but the country has recently seen an uptick in the number of daily virus cases, largely due to new Omicron subvariants.
White House Assistant Press Secretary Kevin Munoz said President Biden's work on vaccines and treatments had been "critical" to easing travel restrictions.
He said the CDC would continue to evaluate Covid data amid the recent rise in cases.
