New advertising rules introduced under the Public Health Alcohol Act of 2018 will prevent drinks companies from promoting their products near schools, playgrounds or on public transport.
The rules will also prohibit alcohol advertising in cinemas for films under the age 18 classification.
The measures also ban children's clothing that promotes alcohol through slogans or imagery.
Drinkaware, the national charity for the prevention and reduction of alcohol misuse and underage drinking in Ireland, has welcomed the new measures. The charity is funded by alcohol and grocery industries.
Drinkaware CEO Sheena Horgan says "This is a positive step forward to tackling Ireland's serious underage drinking problems. The more we reduce children's exposure to alcohol the more we negate the current social norm regarding alcohol."
The 2019 Drinkaware Index shows Irish teenagers are having their first alcoholic drink as young as 14 years old, with a national average of 15.5 years.