Bus Eireann carried an extra one million passengers during 2014, compared to the previous 12 months.
The biggest rise was in Galway with the number of journies up 12%, followed by a 6 per cent rise in Cork, 4 per cent in Limerick and a 1 per cent drop in Waterford.
Dublin saw a 2% rise.
There were more than 35 million bus journies taken across the country last year.
Bus Éireann recently signed a new five year Public Service Obligation (PSO) contract with the National Transport Authority (NTA), which will see the development of further customer service standards and increased reliability and punctuality targets.
This year, the company re-launched its Expressway service with a new campaign and new buses, and the first 20 new luxury coaches will be introduced to the commercial fleet in early 2015.
Commenting on the growth in 2014, and on the outlook for 2015, Bus Éireann chief executive Martin Nolan said: “Bus Éireann has achieved significant turnaround – and boosted customer numbers – over the last twelve months. Further growth is predicted next year in line with the improving economy, which augurs well for the standards of public transport that can be delivered, and the critical role it can play in helping the economy recover even faster.
“However, we also need to continue to invest to provide extra fleet capacity - along with more bus priority measures, in particular on commuter corridors - to combat congestion. Maintaining pressure on our cost base is also key. We will continually strive to enhance services for our customers, and remain at the heart of delivering public transport in Ireland.”