Dublin Coach operates a bus from Kilkenny to Killarney hourly. Tickets cost $10 - $15 and the journey takes 2 h 30 min. Bus Eireann also services this route every 2 hours. Alternatively, Irish Rail operates a train from Kilkenny to Killarney every 4 hours. Tickets cost $18 - $25 and the journey takes 57 min. 2 other operators also service this route.
From Kilkenny, Ormond Road bus to Cork Bus Station, Cork Parnell Place Bus Station then bus to Killarney, Killarney Bus Station. 5 h 5 min 24€. From Kilkenny train to Kildare Train Station, train to Portarlington Train Station, then train to Killarney Train Station. 5 h 12 min 74€. From Kilkenny drive to Killarney. 2 h 22 min 28€.