Aksu Prefecture (; ) is located in mid-western Xinjiang, China. It has an area of 132,500 km² and 2.19 million inhabitants (2003).The name Aksu is Turkic for 'white water'.
The prefecture occupies the northwestern part of the Tarim Basin and the southern slopes of the Tian Shan. The southern part of the prefecture is within the Taklamakan desert. Agriculture is only possible in the areas irrigated by the Tarim River and its glacier-fed tributaries, the Aksu River and the Muzart River.
Of its 2.19 million inhabitants, 71.93% are Uyghur, 26.62% are Han, with the remainder belonging to other ethnicities.