The Bolshoy Yugan is a river in Russia, it flows through the territory of Surgutsky and Nefteyugansky Districts of Khanty-Mansi Autonomous Okrug. A left tributary of the Ob, it discharges into the , a branch of the Ob. The length of the river is 1,063-kilometre (661 mi), its basin area is 34,700-square-kilometre (13,400 sq mi). The average annual water consumption at 118-kilometre (73 mi) from the mouth of the river is 177.67-cubic-metre-per-second (6,274 cu ft/s). Major settlements from the mouth to the source: , , , , , , , .