Ulz River (Mongolian: Улз гол, Russian: Улдза, romanized: Uldza) is a river in Mongolia, which partially flows in Transbaikal, Russia, within the Daursky Nature Reserve. It flows into the Barun-Torey (ru:Барун-Торей) lake.

At about 20km before the mouth a branch to the right is split named Teliin Gol [ceb] (телийн гол) (which until 2013 was dry for many years) which delivers water into the river Шуду-Гол (Shudu Gol), which sinks into the lake Khökh Nuur.

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