Bus Éireann has signed a new €1.2bn five-year contract with the National Transport Authority (NTA).
The deal covers the provision of 206 Public Service Obligation routes nationwide up to the end of November 2029.
"We look forward to continuing to build on the momentum of sustainable journey growth which is now evident for public transport and developing continued service improvements with the NTA, over the next five years," said Bus Éireann Chairperson Miriam Hughes.
"This includes our electrification and decarbonisation programme for our new fleet of public buses that serve our regional city and town networks and continuing to enhance service reliability for all our customers across Ireland."
More than 250 million customer journeys will be provided during the period of the contract.
"We are delighted to award Bus Éireann a new five-year direct award contract, reaffirming our commitment to reliable, sustainable, and customer-focused public transport particularly as passenger numbers on PSO services nationwide continue to grow," said Anne Graham, chief executive of the NTA.
"We look forward to working together to enhance services for the public and support a more connected, greener Ireland."
Last year Bus Éireann carried 107m passengers across its network.
This year the company began the transition of the first regional city service, in Limerick, to zero emission fleet.
