The National Transport Authority has ordered 120 double decker battery-electric buses which will enter passenger services next year.
It is part of a plan to decarbonise the country's public transport fleet.
The double decker buses were purchased from a company called Wrightbus at a cost of €80.4 million.
Minister for Transport Eamon Ryan said the buses were a sign of where the country was going.
He said the buses were already being used in Belfast and were working very well.
Electric buses would become the norm in every city across the country, he said.
"This is the future, electrifying everything in transport, cutting out the carbon, using our own local fuels and our own local buses."
These buses will be the first battery electric double decker buses to be added to the national fleet.
It is part of a framework which will provide 800 zero emission double decker buses over five years.
National Transport Authority CEO Anne Graham said: "Well it represents a significant order first, but it's also a change now in moving our fleet from fully diesel to fully electric.
"We need to encourage more people to use public transport, walk and cycle and to reduce their use of the private car."
One hundred of the buses are destined for Dublin Bus and 20 will go to Bus Éireann.
Bus Éireann Chief Executive Stephen Kent said: "We will be putting it firstly into the streets of Limerick.
"By next year that will all arrive in, which means we will have zero emission for the first time on double deck buses. It will be a quieter ride for our customers and most of all good for the environment as well."
The buses are expected to enter passenger service next year.
Wrightbus Managing Director Neil Collins described the deal as "historic".
"This deal further cements the reputation we have built in the zero-emission sector, and follows hot on the heels of historic deals in Australia and Germany.
"This shows our ambition to be at the forefront of the zero emission drive in cities, towns and rural areas across the world," he added.
