Pubs, restaurants, cinemas and all live venues are to close nightly from 8pm from Sunday until the end of January.
That was the major move made by Government tonight after new recommendations by the National Public Health Emergency Team.
It follows an explosion in the Omicron strain of the virus.
Nphet had asked for a 5pm closing time which was met with a major backlash.
Sport will also be hit by the new measures.
Under the measures the number of spectators attending sporting events are to be limited to 50% capacity, to a maximum of 5,000 people.
Weddings are to be limited to 100 people and end at midnight, under the proposals agreed by Cabinet.
There are no changes to the number allowed for household visits, which will remain set at four households.
There are also no changes to domestic travel for the Christmas period.
Cabinet has also agreed that the measures stay in place until 30 January, but this date will be kept under review.
Taoiseach Micheál Martin said this evening that, left unchecked, the new Omicron variant represented a serious threat to the health system, and all of society.
However, he stressed that the country is not in as bad a position as it was a year ago.
Mr Martin said the variant was now “exploding throughout Europe”, adding that “it is here, it is in our country… we are going to see a massive rise in infection”.
“We are likely to see infections far in excess of anything we’ve seen to date. It is that serious,” he said.
He added: “The challenge we face is how we slow the rise in infection, and how we prevent it from going out of control”.
