Changji (Chinese: 昌吉; pinyin: Chāngjí; Uyghur: سانجى, ULY: Sanji) is a county-level city of about 390,000 inhabitants in northern Xinjiang, People's Republic of China, serving as the seat of Changji Hui Autonomous Prefecture.
A Federation of Industry and Commerce is at Changji. In the area around Changji crop growing, animal husbandry and oil crop growing are important parts of the economy. Changji is the home of Changji University.
Changji is served by China National Highway 312, the Northern Xinjiang and the Second Ürümqi-Jinghe Railways.