Lanzhou (UK: , US: ; simplified Chinese: 兰州; traditional Chinese: 蘭州; pinyin: Lánzhōu) is the capital and largest city of Gansu Province in Northwest China. Located on the banks of the Yellow River, it is a key regional transportation hub, connecting areas further west by rail to the eastern half of the country. Historically, it has been a major link on the Northern Silk Road and it stands to become a major hub on the New Eurasian Land Bridge. The city is also a center for heavy industry and petrochemical industry.

Lanzhou is one of the top 70 major cities in the world by scientific research output as tracked by the Nature Index. The city hosts several research institutions, including, Lanzhou University, Lanzhou University of Technology, Northwest Normal University, Lanzhou Jiaotong University, Gansu University of Chinese Medicine, and Gansu Agricultural University. Notably, Lanzhou University is one of China's prestige universities as a member of the Project 985.