Barely 16,000 people entered Ireland by air or sea during the entire month of April - well below 1pc of the normal flow of travellers.
The Central Statistics Office called it "an unprecedented collapse in overseas travel to and from Ireland".
Whereas more than 1.7 million people travelled here in April 2019, only 12,100 arrived at Ireland's airports last month and just 4,000 came by ferry.
Three-quarters of travellers came from Britain, and just 1,100 from the United States - which accounted for nearly 155,000 people entering the State in April a year ago.
The figures were similarly barren for travel in the other direction, with just 17,700 people leaving Ireland last month by sea or air - 99pc lower than in April 2019.
The most popular destinations from Ireland were Britain (8,800), the Netherlands (2,000) and France (1,400).
Only 500 people here flew to the US, down from more than 158,000 a year ago.
The report found that not one soul travelled to Ireland from Italy, Spain or Switzerland for the entire month, while about 100 people each made it to Italy and Spain - and none to Switzerland.
Travel also totally halted in both directions with the Isle of Man and the Channel Islands of Jersey and Guernsey.
The CSO report did not compile any land arrivals or departures with the UK via the Border.
It also offered no breakdown of travellers by national residence because, since the March lockdown, CSO enumerators have stopped gathering data in person at airports and ferry terminals. "The information is compiled primarily from statistics provided by the DAA, together with data from other air and seaports," the CSO said.
Airlines are increasingly hopeful of resuming substantial services in July, given that many European nations are easing travel restrictions more quickly than Ireland.
Ryanair says it plans to operate two-fifths of its usual summer schedule starting on July 1 - and has begun to openly challenge the Government's rationale behind the lockdown regime and social-distancing protocols.
Current advice from the Department of Foreign Affairs and Trade is to avoid all non-essential travel overseas until further notice.
Aer Lingus currently offers flights to three destinations in the US - New York JFK, Boston and Chicago. Its website also displays tickets for sale starting on July 20 out of Dublin to Los Angeles, San Francisco, Orlando, Washington DC and Hartford, Connecticut.
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