Pubs, restaurants, cinemas, and other hospitality venues have been handed an 8pm curfew, set to remain in place until at least 30 January.
Venues will also run at a reduced capacity, whichever is lower of 1,000 people or 50% for indoor venues, and whichever is lower out of 5,000 people or 50% for outdoor venues.
The measures have been brought in after Omicron became the country’s dominant Covid-19 strain, just two weeks after cases were first reported on the island.
Deputy prime minister Leo Varadkar said that he doesn’t expect the need for tighter controls, telling broadcaster RTE: "If we have to, we will do whatever is necessary... but we don't anticipate that will be necessary."
There has been opposition to the announcement, with Padraig Cribben, chief executive of the Vintners’ Federation of Ireland warning that the “decision will decimate the trade that was already on its knees”.
“Christmas was the one chance we had to recoup some of the losses amassed earlier in the year but we’re now in a situation where staff will lose their jobs and pubs will shut one week before Christmas as they see little point in opening under these conditions,” he said.
“Given the relentless public health message over the past number of weeks to avoid socialising the public had already cancelled bookings in record numbers.
“It’s difficult to overstate the feeling in the trade, publicans and their staff are at the absolute limits of their endurance.”
