21% of Irish adults are classified as hazardous drinkers, according to the 2019 Drinkaware Index.
The report, which was published today, also found that 23% are at risk of becoming hazardous drinkers.
The study highlights "a deep-rooted and broad acceptance of excessive drinking as our cultural norm" with 44% of people reporting weekly drinking.
The research found what Drinkaware called "worrying trends" in alcohol consumption for under-25s.
Over a third (34%) of under-25s report binge drinking on a weekly basis.
Binge drinking is classified in the report as having six or more standard drinks in one sitting. The figure is down at 18% when looking at the whole drinking population.
It found that the current generation of under-25s had their first alcoholic drink at 14.3 years, compared to the national average of 15.5 years.
It also highlighted that 64% of under-25s drink as a coping mechanism against a 50% national average.
Drinkaware say the survey shows "that the majority of Irish adults have little to no awareness of what constitutes low-risk drinking".
98% of respondents could not identify the HSE weekly low-risk alcohol guidelines, while 24% acknowledged that their current drinking levels may cause future health problems.
Meanwhile, 74% agree with the statement that drinking to excess is just a part of Irish culture.
The research was carried out by Behaviour & Attitudes with a nationally representative sample of 1,000 adults.
Sheena Horgan, CEO of Drinkaware, said: "The Drinkaware Index research highlights that a significant number of Irish adults are drinking at a level that may be putting their health at risk."
She said that while "the negative impact of alcohol in Irish society is widely known" there is less comprehensive "published analysis on the motivational drivers, the behaviours and attitudes of Irish society towards alcohol across different demographics and ages".
Ms Horgan added that the 2019 Index "has quantified and exposed, for the first time, the collective complacency and cultural acceptance surrounding Irish drinking patterns.
"To get to the heart of the problem, we need to examine and reassess some of our deep-rooted cultural norms and wide acceptance that we are simply excessive drinkers by virtue of our national heritage."