The Sil is a river in León (Castile and León) and Galicia, Spain, a tributary of the Miño. Its total length is . The source of the Sil is in the Cantabrian Mountains in the Leonese town of Villablino. It flows through the provinces of León and Ourense. The largest city on the Sil is Ponferrada (León). The Sil flows into the Miño upstream from Ourense.