Hi Christine,
Bus Éireann is the best option for public transport from Galway to Westport. They have a direct
service 456 and takes about an hour and a half to get there. 🚌
Buying tickets online is the best way to guarantee a place on the bus on the day and time you wish. You can just pay the driver on the day if there are seats available at the time if this suits you better.
Both Galway and Westport are lovely places to see and the route takes you through some wonderful areas too.
What have you planned for your time in Westport?