Discovery Communications, the owner of Eurosport, has paid €1.3bn for exclusive pan-European rights to screen the Olympic Games from 2018 to 2024.
National public broadcasters such as RTÉ have traditionally held individual rights to the event.
It remains unclear whether this situation will change under the new deal - the European rights for the Rio 2016 Olympics were initially purchased by sports marketing company SportFive, which then sub-licensed the rights to individual broadcasters such as RTÉ.
"Discovery will sub-license a portion of the rights in many markets across Europe"
Under the 2009 Broadcasting Act, the summer Olympics is designated as a major event and must be available free-to-air in Ireland.
Eurosport is not available free-to-air in Ireland. Assuming Discovery does not acquire a free-to-air channel in this country, it would have to sub-licence the rights to one of the current free-to-air TV broadcasters - RTÉ, TV3, TG4 or UTV Ireland.
Discovery says it has made a commitment to the IOC that a certain amount of the Games will be available on free-to-air TV. It confirmed it will sub-license 'a minimum of 200 hours of the Olympic Games and 100 hours of the Olympic Winter Games "in many markets across Europe."
RTÉ holds exclusive Irish rights to the Rio 2016 Olympics across all platforms. Rio 2016 will be the 14th Olympic Games to be shown to be shown by RTÉ on Irish television, the first being Tokyo 1964.
In a statement this afternoon, RTÉ said it was disappointed, but stressed that it was "too early to say definitively that RTÉ won’t broadcast the Olympics in 2020 and 2024."
"It should be noted that rights to Rio 2016 were bought by RTÉ through a third party agency when the EBU failed in its bid for those games and Discovery Channel have said today that they will ‘sub-license a portion of the rights in many markets across Europe’."
RTÉ said it wqould make every effort to secure the rights for the Summer Olympic Games in 2020 and 2024 "so that Irish viewers can watch home-produced, relevant coverage of Irish athletes competing both in Tokyo in 2020 and at the 2024 Summer games - something that all countries would lose in the event of pan-European coverage.
"RTÉ remains optimistic that a solution will be found"
This new deal includes 53 countries in Europe, but excludes Russia. The French and British rights for 2018 and 2020 are excluded also - those rights have already been sold to the BBC and France Television.
Across Europe, the agreement covers the Winter Games in PyeongChang, South Korea, in 2018 and the 2020 Games in Tokyo, as well as the Olympic Games in 2022 and 2024, the host cities of which have yet to be selected.
The International Olympic Committee says it chose Discovery after "a competitive auction" that attracted more than ten bids, said Timo Lumme, a television and marketing executive at the IOC.
"This is the first time we have licensed these rights to a single media company to manage and broadcast all the games across all the platforms," said Lumme.
The IOC said the European broadcast rights from the four Olympic Games from 2018 to 2024 could bring in €1.6 billion total, about 10% higher than the last period.
Discovery's chairman is billionaire cable entrepreneur John Malone, who also owns a significant stake in Europe's largest cable company Liberty Global.