Munster Technological University in the Republic of Ireland confirms that the incident affecting its computers is a ransomware attack.
The Irish Dancing Commission, Ireland's governing body for Irish dancing, appoints a former judge to investigate claims of prominent dance schools and teachers fixing competitions.
Ireland reports its first case of the B.1.525 variant first detected in Nigeria.
Taoiseach Micheál Martin announces a return of "Level 5" lockdown in the country with specific adjustments from Christmas Eve until at least January 12.
Ireland "significantly" tightens restrictions after a rapid increase in the number of COVID-19 cases over the past two weeks. All businesses are told to let employees work from home, new limits are placed on outdoor gatherings, and the government warns people to avoid public transport. The new rules will be in place until at least September 13.
Ireland becomes the first European nation to be allowed to export beef to the United States since the mad cow disease scare 15 years ago.
The funeral of Ian McKeever, who was killed by a lightning strike on Mount Kilimanjaro, occurs in County Wicklow, Ireland.
Prince Albert II of Monaco and his fiancée Charlene Wittstock arrive in Ireland for a state visit, 50 years after the visit of Prince Rainier and Hollywood actress Princess Grace. They are to dine at a state banquet hosted by President Mary McAleese and her husband at Áras an Uachtaráin.
Irish Minister for Arts, Sport and Tourism Martin Cullen resigns from politics after seeking medical advice.
Irish Minister for Defence Willie O'Dea resigns after a controversy surrounding his remarks on a rival politician's relationship with brothels but denies claims by opposition party Fine Gael that he has committed perjury. Taoiseach Brian Cowen assigns himself temporary responsibility for the Department of Defence.