The Aldan River is the second-longest tributary of the Lena River in eastern Siberia. The river is 2,273 km long, of which around 1,600 km is navigable.

It rises in the Stanovoy Mountains south west of Neryungri , then north east past Aldan and through Tommot , Ust'-Maya , El'dikan and Khandyga before turning north west and joining the Lena near Batamay .

The river's main tributaries are the River Amga , River Uchur and River Maya . Its basin is known for gold and for Cambrian fossils.