Râu Sadului (Hungarian: Riuszád) is a commune in Sibiu County, Transylvania, Romania, at the foothills of the Cindrel Mountains, 30 km (19 mi) south of the county capital Sibiu, in the Mărginimea Sibiului ethnographical area. It is composed of a single village, Râu Sadului. At the 2011 census, 100% of inhabitants were ethnic Romanians.