The South Circular Road (Irish: An Cuarbhóthar Theas), designated as the R811 regional road, is a road in Dublin, Ireland. One of the longest in the city, it runs from Islandbridge in the west, through Rialto and Dolphin's Barn to Portobello, near the centre. It runs mainly through residential areas and is used by numerous bus routes. It is the southside equivalent of the North Circular Road.