The head of the Irish Tourism Industry Confederation, Eoghan O'Mara Walsh, says the sector will suffer as a result of the 14-day quarantine requirement.
Currently, people arriving from abroad in Ireland are required to self-isolate for two weeks.
Mr O'Mara-Walsh says: "75% of the tourism economy is international visitation. So the domestic market is important and that's a given and please god the domestic market will support the Irish tourism industry this summer as the restrictions are lifted.
"But the bulk of the tourism economy is made up of international visitation and we need to see a return to that obviously subject to public health concerns."
Covid-19 passenger locator forms will be used to make sure people who travel here are staying where they said they would.
From today, anyone arriving from overseas must provide details of where they will be self-isolating and their contact information.
Failure to do so could lead to a fine of up to €2,500 or a jail term of up to six months.
Chief medical officer Tony Holohan says airlines and airports will help ensure forms are filled out.
He says: "We expect to have not only the airlines but the airport authorities helping us in the implementation of those regulations provided for by legislation."