The country's pubs and hotel bars shut down last night to stem the spread of Covid-19, leaving 50,000 bar workers out of work and opening the possibility some pubs might never open again.
Health Minister Simon Harris made the announcement just hours after video footage of a large gathering in a Dublin city pub went viral, causing widespread anger that social distancing requests were not being observed.
He said many pubs have found it "simply not possible to comply" with restrictions on numbers in indoor and outdoor gatherings. "The pub is a place of social interaction. We know when people consume alcohol it can remove inhibitions. It's hard to tell people in such an environment to keep their social distance," he said.
He met with the chief medical officer, senior Government officials and the representative bodies of the publicans across the country yesterday.
"In the interests of public health, all pubs and all bars in Ireland will close this evening until March 29.
"This will be kept under review," he said.
Some 7,400 pubs will close.
The closure - ahead of the peak St Patrick's Day trading period - is set to cost the industry at least €100m but could soar further if normal pub and club trade cannot be resumed on March 29.
Restaurants, cafés and fast food outlets will remain open though the situation is being carefully monitored.
Government officials, including public health experts, met with the Licensed Vintners Association (LVA) and the Vintners' Federation of Ireland (VFI) at an emergency meeting in Dublin.
The public has also been urged not to organise or participate in any parties in private houses or other venues which would put other citizens' health at risk.
Both the LVA and VFI supported the closure decision and urged all their members to comply with the Government's shutdown request. However, hundreds of Irish pubs, cafés and restaurants had already opted to voluntarily shut.
All Temple Bar pubs and clubs in Dublin had indicated at lunchtime yesterday they would close after operators said it was virtually impossible to impose recommended social distancing guidelines.
Among the famous Dublin pubs and clubs to signal closure well before the shutdown announcement were Copper Faced Jacks, Peadar Browns, Ohana, Zozimus, Grogan's Castle, The Camden and The Back Page, The Bernard Shaw and The Black Wolf.
Leo Varadkar - reacting to alarm at so-called student 'virus parties' and scenes of packed Dublin pubs over the weekend - warned the Government would seek special enforcement powers from the Dáil and Seanad if required. He warned revellers that irresponsible social behaviour risked spreading the virus and making vulnerable people "very, very sick".
Leading oncologist Professor John Crown had urged for several days that the Government close all bars and clubs.
The Bishop of Limerick, Dr Brendan Leahy, criticised those who insisted on carrying on their social lives as normal last weekend despite the threat. The LVA also hit out at "a small number of pubs flouting the coronavirus guidance - these pubs have been seriously irresponsible and their behaviour is completely and utterly unacceptable".
Immunology experts have criticised the British government's strategy of allowing large numbers of people to become infected with coronavirus to develop "herd immunity" so that the more vulnerable do not contract the disease.