Ireland has fallen two places from 14 to 16 in the 2018 World Press Freedom Index, due to what a media watchdog said is the "highly concentrated nature of media ownership in Ireland".
Reporters without Borders added that this "continues to pose a major threat to press freedom".
It said Independent News & Media (INM) controls much of the daily and Sunday newspaper market, while broadcasting is dominated by RTÉ.
Norway is first for the second year running, followed by Sweden, while North Korea remains at the bottom of the index.
Press freedom around the world is under threat from a combination of US President Donald Trump, Russia and China's bid to crush all dissent, RSF said.
Reporters Without Borders (RSF) has accused the world's three superpower nations of leading the charge against press freedom, with Mr Trump regularly launching personal attacks on journalists and Beijing exporting its "media control model" to strangle dissent elsewhere in Asia.
The US has fallen again in the index under President Trump to 45th place, with RSF citing his continued verbal attacks against the media generally and his description of journalists as being "enemies of the people", a term once used by Joseph Stalin.
In recent twitter posts he has launched personal attacks against journalists such as NBC's Chuck Todd and "third rate reporter named Maggie Haberman" of the New York Times.
Sleepy Eyes Chuck Todd of Fake News NBC just stated that we have given up so much in our negotiations with North Korea, and they have given up nothing. Wow, we haven’t given up anything & they have agreed to denuclearization (so great for World), site closure, & no more testing!
— Donald J. Trump (@realDonaldTrump) April 22, 2018
The New York Times and a third rate reporter named Maggie Haberman, known as a Crooked H flunkie who I don’t speak to and have nothing to do with, are going out of their way to destroy Michael Cohen and his relationship with me in the hope that he will "flip." They use....
— Donald J. Trump (@realDonaldTrump) April 21, 2018
