The Siligir (; ) is a river in Yakutia (Sakha Republic), Russia. It is the largest right tributary of the Olenyok with a length of â long counting the Orto-Siligir stretch of its upper course. Its drainage basin area is .
The river flows just north of the Arctic Circle across a lonely, desolate area of Olenyoksky District devoid of settlements. There are very large bitumen deposits along the Siligir basin.
The Siligir is formed in the Central Siberian Plateau at the confluence of the long Orto-Siligir (ÃÂÃÂÃÂþ-áøûøóøÃÂ) and the long Usuk-Siligir (ãÃÂÃÂú-áøûøóøÃÂ). The river flows initially northwards, bending to the NNE after a stretch, and then to the northeast. Finally it bends again to the north and meets the right bank of the Olenyok from its mouth. The confluence is downstream of Olenyok village, one of the few inhabited localities of the area. The river is frozen between early October and the second half of May.
The Siligir has some very large tributaries, such as the long Onnyo-Siligir (; ) and the long Siligirkeen (áøûøóøÃÂúÃÂÃÂý), both from the left.
The main fish species found in the waters of the Siligir are lenok, taimen, grayling, pike and perch. In some stretches there are whitefish and nelma.