| Country: | IRL |
| Photo Notes: | Ballyhest Crossroads, where the R678 and R676 meet. |
| Type: | R |
| Route: | 678 |
| Length Km: | 30.9 |
| Terminus A: | R680 R671 Carrick-on-Suir (Raheen Road) |
| Junction: | Enters County Cork Passes through Rathgormack R676 Ballyhest Crosses River Clodiagh |
| Terminus B: | R677 Lowry's Bridge |
The R678 road is a regional road in Ireland, located in County Tipperary and County Waterford.[1] [2]