The Vilyuy River is a tributary of the Lena in eastern Siberia. The river is approximately 2,650 km long, of which around 1,450 km is navigable.

The Vilyuy's source lies near Ekonda , in the north of the Central Siberian Plateau. It then flows south east, through a lake and the towns of Cherynshevskiy , Suntar , Nyurba and Verkhnevilyuysk before joining the Lena near Sangar .

The river is known for the diamond mines established along it since the 1950s.