Kucha or Kuche (also: Kuçar, Kuchar) Uyghur (كۇچار), Chinese Simplified: 库车; Traditional: 庫車; pinyin Kùchē; also romanized as Qiuzi, Qiuci, Chiu-tzu, Kiu-che, Kuei-tzu from the traditional Chinese forms 屈支 屈茨; 龜玆; 龟兹, 丘玆, also Po (bai in pinyin?); Sanskrit: Kucina, Standard Tibetan: Kutsahiyui was an ancient Buddhist kingdom located on the branch of the Silk Road that ran along the northern edge of the Taklamakan Desert in the Tarim Basin and south of the Muzat River. (The area lies in present day Aksu Prefecture, Xinjiang, China; Kuqa City itself is the county seat of that prefecture's Kuqa County). Its population was given as 74,632 in 1990.

According to the Book of Han, Kucha was the largest of the 'Thirty-six kingdoms of the Western Regions,' with a population of 81,317, including 21,076 persons able to bear arms. During the periods of Tang domination during the Early Middle Ages, the city of Kucha was usually one of the 'Four Garrisons' of An-hsi (Anxi) the 'Pacified West'., typically the capital of it. During periods of Tibetan domination it was usually at least semi-independent. It fell under Uighur domination and became an important center of the later Uighur Kingdom after the Kirghiz destruction of the Uighur steppe empire in 840.