Lanzhou or Lan Prefecture (嵐州) was a zhou (prefecture) in imperial China seated in modern Lan County in Shanxi, China. It existed (intermittently) from 623 to 1369.

The administrative region of Lanzhou in the Tang dynasty is in Shanxi. It probably includes parts of modern:

• Under the administration of Lüliang:
  • Lan County
  • Xing County
• Under the administration of Xinzhou:
  • Jingle County
  • Kelan County

• Shi Weile, ed. (2005). Zhongguo Lishi Diming Da Cidian (中国历史地名大词典) [Large Dictionary of Chinese Historical Place Names] (in Chinese). China Social Sciences Press. pp. 1272–1273. ISBN 7-5004-4929-1.