Uokil (Ukil, Vokil, Augal) is one of Yuezhi tribes, defeated and displaced by the Hun's expansion in the 2nd century BC. Uokil may have been one of the two Yuezhi dynastic tribes. Traces of ethnonym "Uokil" are found in the East Mongolia and Manchuria territories in the Syanbi (Ch. 鲜卑 Xianbei), ancient Turkic, and Mongolian time. They may be connected to or descended from the:
Before the end of the 4th century BCE, the country Yuezhi (Chinese Ngiw.at-tie) extended west from the northern bend of the Yellow River (in modern Gansu). The vassals of the Yuezhi came to include the Xiongnu.
In about 210-200 BC, the Xiongnu leader Modu Chanyu, a former hostage of the Yuezhi, conquered the Mongolian Plain, subjugating several peoples. In about 176 BC Mody Chanyu rebelled against and attacked the Yuezhi.