Bus Éireann is to create 120 new jobs and provide an increase in services across the country.
The upgrade will be funded by the National Transport Authority through the Government's July Stimulus package.
The State transport company says it is the most significant single enhancement of services in more than 15 years.
It includes both new services and increased frequency on existing routes.
Recruitment is ongoing for 120 driver posts in Mayo, Cork, Louth and Limerick.
Enhanced services will be rolled out in Navan increasing services there to two routes every half an hour, seven days a week.
A new cross city service is to be put in place in Cork while Tipperary will benefit from a daily bus service to Limerick and Nenagh for the first time.
There will also be increased frequency on popular routes in Drogheda town, Limerick city and on the west Clare network.
The announcement comes three months after Bus Éireann announced the suspension of several Expressway routes as a result of financial pressures brought about by the Covid-19 pandemic.
Bus Éireann CEO Stephen Kent said expanded services will be in place over the next three to four weeks in Navan and Drogheda in response to feedback from customers.
Speaking on RTÉ's Morning Ireland, he said that "as sure as Christmas is coming, people will return to public transport" and expects further growth in passenger numbers in the regions.
He said that there are capacity issues on some services in the run up to Christmas due to restrictions on numbers who can travel and asked for "forbearance" from passengers.