The N78 road is a national secondary road in Ireland. The  road links the N77 national secondary road north of Kilkenny, County Kilkenny to the M9 national primary route at Mullamast in County Kildare.
The N78 road is an Irish national secondary highway that connects to the N77 highway north of Kilkenny, County Kilkenny, and then merges with the larger M9 highway at Mullamast in County Kildare.