Xienianhe River

Selenga River (Селенга Сэлэнгэ)
Selenge
Selenga River in Russia
Primary source	Delgermörön River
Secondary source	Ider River
Source confluence	Olon golyn bilchir
- location	Khövsgöl, Mongolia
- coordinates	49°15′40″N 100°40′45″E / 49.26111°N 100.67917°E / 49.26111; 100.67917
Mouth	Lake Baikal
Length	992 km (616 mi)
Basin	447,000 km2 (172,588 sq mi)
Discharge	for Ust-Kyakhta
- average	284 m3/s (10,029 cu ft/s)
- max	601 m3/s (21,224 cu ft/s) August
- min	23 m3/s (812 cu ft/s) February

The Selenga River (Selenge River, Mongolian: Сэлэнгэ мөрөн, Selenge mörön; Buryat: Сэлэнгэ гол, Selenge gol, Сэлэнгэ мүрэн, Selenge müren; Russian: Селенга́) is a major river in Mongolia and Buryatia, Russia. Its source rivers are the Ider River and the Delgermörön river. It flows into Lake Baikal and has a length of 992 kilometres (616 mi) or 1,024 kilometres (636 mi), according to other sources. The Selenga River is the headwaters of the Yenisei-Angara River system. Carrying 935 cubic metres per second (33,000 cu ft/s) of water into Lake Baikal, it comprises almost half of the riverine inflow and forms a wide delta of 680 square kilometres (260 sq mi), when it reaches the lake.

The name derives from Mongolian verb "seleh" (to swim). According to another version, the name originated with the Evenki sele 'iron' + -nga (suffix) .Selenge Province in Mongolia is derived from the name of this river.