All people returning from Italy and Spain will be met by public health officials at the airport and asked to restrict their movements for two weeks.
The move comes as the Government continues to ramp up precautions to prevent the spread of the coronavirus.
Irish people have now been advised against all non-essential travel to any part of Spain - including the Balearic and Canary Islands. Italy is already in total ’’lockdown’’ due to the spread of the virus.
Health Minister Simon Harris said the decision was recommended by the National Public Health Emergency Team on Thursday night and came into force this morning.
"People who come back from these countries will be given information at the airport and that information will tell them to restrict their movements for the next two weeks. What that effectively means is to not go to work, to lessen your social contacts," he said on RTÉ’s Morning Ireland.
"The reality of this virus is that it is fast evolving. It was really gripping Italy and still is but it has now spread to Spain and indeed we will have to monitor this in the coming days as we can see worrying trends in other countries like France and Germany and the UK.
"If people choose to travel to an area where we tell people its unnecessary to travel or indeed an area where it becomes unnecessary to travel to, we will have to tell those people to take additional precautions when they return to our country," said Mr Harris.
However, the health minister said the restrictions on people returning from Italy and Spain would not apply to the thousands of Irish people returning from the Cheltenham festival.
"The Public Health Emergency Team did consider this specifically. It is a statement of fact that, as of now, the UK is not deemed to be an affected area in the same way as Spain or Italy so what will happen to all people who will come back through the airports, including those from Cheltenham, is they will all receive information on things to watch out for in terms of symptoms and the likes but there’s no specific restrictions on those," said Mr Harris.
The director of Cheltenham race course Ian Renton was forced to defend the decision to proceed with the festival amid mounting criticism that other large sporting events are being postponed all around the world.
"It’s certainly not business as usual. We have certainly taken significant precautions and followed the Government’s advice over here and I think there’s certainly a massive amount of evidence that our racegoers are heeding that advice particularly if there is any reason for them not to come racing they are not doing so.
"We have seen a number of people choosing not to come to the festival over the past three days and today as well...I believe we have done everything we can to put on an event of this nature and ensure that the environment is right for our racegoers," he said.