That includes not going to work and social events.
Anyone returning from Spain or Italy will have to restrict their movements for the next two weeks, including not going to work and reducing their social interactions.
The National Public Health Emergency Team made the decision in a bid to stop the spread of the coronavirus.
Environmental health workers will meet those returning at the airport to tell them of the restrictions, while people coming back from Cheltenham won’t have to self-isolate, but will be met by health staff.
“All we can do is flatten that curve, make sure we don’t all get it at the same time,” Health Miniter Simon Harris told RTE.
Yesterday saw 27 new confirmed cases of coronavirus in the Republic, bringing the total to 70.