The Chief Medical Officer is urging people to only meet over the coming days with those with whom they intend spending Christmas Day.
Dr Tony Holohan says the highly transmissible Omicron variant now accounts for two thirds of new Covid cases here.
It comes after over 5,200 new cases of the virus were confirmed yesterday evening.
The five-day moving average has grown to 5,233 - a 22 per cent increase on a week ago.
Mayo currently has the lowest rates of Covid-19 nationally, followed by Roscommon and Sligo.