The Onon is a river in Mongolia and Russia. It is long, and has a drainage basin of .
Course
It originates at the eastern slope of the Khentii Mountains. For 298 km it flows within Mongolia, before entering the Khentei-Daur Highlands region of the Russian Far East flowing along the Stanovik Range. In its lower reaches it flows between the Mogoytuy (Могойтуйский хребет) and the Borshchovochny (Борщовочный хребет) mountain ranges. It joins with the Ingoda to form the Shilka. Its river valley forms the eastern limit of the Khentei-Daur Highlands. Its main tributaries are the Khurkhyn Gol, Borzya and Unda from the right, and the Agutsa, Kyra and Aga from the left.
See also
- List of rivers of Mongolia