The R660 road is a regional road in County Tipperary, Ireland, which runs south–north from the Cashel to Thurles. En route it passes through the village of Holycross, where it crosses the River Suir and passes the walls of Holy Cross Abbey. The route is 21 km (13 mi) long.

• Roads in Ireland
• National primary road
• National secondary road

• Roads Act 1993 (Classification of Regional Roads) Order 2006 – Department of Transport