It will see free travel on Bus Éireann, Iarnród Éireann, Luas, DART and Dublin Bus
A new scheme which grants free public transport to children under five-years-old is coming into force.
From Friday December 1st, all under-fives travelling on subsidised public transport services becomes free.
As part of its fares determination, the National Transport Authority (NTA) announced that all under-fives get to travel free on public transport - including Bus Éireann, Iarnród Éireann, Luas, DART and Dublin Bus.
The authority says it recognises that the cost of travel with a young family can be expensive - adding that this move "marks another step towards making sustainable transport a more affordable option for more families."
Anne Graham, NTA chief executive Officer said: "Today's development will be good news for families, particularly around this time of year as people get geared up for going into town to do Christmas shopping and to see Santa Claus.
"NTA has been taking steps to reduce the cost to families of using public transport since 2014.
"These include extending child fare eligibility to a person's 19th birthday, and introducing 'Kids Go Free' Leap promotions during the summer.
"This is something that we will continue to work on in the years ahead."
Among other fare changes that take effect from Friday is the expansion of city bus zones in regional cities, which means passengers on about 3m journeys on Bus Éireann will be paying lower fares in 2018 than in 2017.
Following an analysis of the fare zones the cities of Cork, Limerick, Galway an extended city fare zone will be in place.
The NTA says this will mean "significant savings" for commuters travelling from one of the new areas which are now included in the city fare zone.