The Uly-Zhylanshyk (Kazakh: Ұлы Жыланшық, Ūly Jy̌lanšyq) is a river in Kazakhstan.
- Geography: It is located in the northern part of the Turgay Depression (also spelled Turgai Depression) within the Kostanay Region of Kazakhstan.
- Hydrology: The Uly-Zhylanshyk is an endorheic river, meaning it does not flow into an ocean or sea. Instead, it typically empties into Lake Sarykopa, a large salt lake in the Turgay Depression. During periods of high water, especially in spring, its waters can contribute to the intermittent filling of Lake Sarykopa. In dry periods, sections of the river may dry up or form isolated pools.
- Catchment Area: The river and its basin are characterized by a semi-arid to arid climate, typical of the steppe and desert regions of Central Asia. Its flow is primarily fed by snowmelt and seasonal rainfall.
- Significance: While not a major navigational river, it is an important local water source in an otherwise dry region, supporting local ecosystems and, historically, nomadic life. Its basin is part of a larger system of internal drainage that defines much of the Turgay Depression.