| Country: | IRL |
| Type: | R |
| Image Notes: | The R665 road between Ardfinnan and Clogheen |
| Route: | 665 |
| Terminus A: | N73 at Stag Park, County Cork |
| Junction: |
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| Terminus B: | R884 at Irishtown Upper, Clonmel, County Tipperary |
| Previous Type: | R |
| Previous Route: | 664 |
| Next Type: | R |
| Next Route: | 666 |
The R665 road is a regional road in Ireland. The route runs from Mitchelstown to Clonmel via Ballyporeen, Clogheen and Ardfinnan, passing through parts of counties Cork, Tipperary and Waterford. The R665 was once a key part of the historic route from Dublin to Cork and was mapped as such as late as 1778. A turnpike road, it was also a key part of the route linking Mallow with Dublin, via today's N73.[1]