a VirtualTourist member
Is there a bus that runs from Killarney to Cork city
will give you all Irish bus routes and times, and has a journeyplanner.
Expressway service 40A runs from Rosslare to Tralee, stopping at Killarney and Cork. Journey takes around 1h 35m.
There's a regular bus service from Cork to Killarney and back. Yes, the buseireann site is the one to search and there are several services a day.