The Allakh-Yun (Russian: Аллах-Юнь, Yakut: Ааллаах Үүн, Aallaax Üün) is a river in Sakha Republic and Khabarovsk Krai, Russia.

The river cuts through the Ulakhan-Bom Ridge, before flowing into the Aldan by the southern end of the Kyllakh Range, at an elevation of 146 metres (479 ft), approximately 20 kilometres (12 mi) from the settlement of Eldikan.

The surrounding area is very sparsely settled, with the few settlements that do exist on the river, such as Allakh-Yun, Zvyodochka and Solnechny, having originated as gold-mining centres in the 1930s.

With the economic crisis arising after the breakup of the Soviet Union and subsequent cessation of mining activities, the area's population dropped from over 8,000 in 1989 to around 1,500 in 2010.

The 300-kilometre (190 mi) long unsealed road connecting Eldikan with Yugoryonok on the Yudoma River crosses the Allakh-Yun on a concrete bridge north of Solnechny.