| Bai Prefecture (白州) | |
| Also Known As: | Nanchang Commandery (南昌郡) |
| Preceded By: | Nan Prefecture (南州) |
| Start: | 623 (Tang dynasty) |
| End: | 1136 (Song dynasty) |
| Populationfirst: | 9,498 |
| Populationfirstyear: | 740s or 750s |
| Populationsecond: | Unknown, 4,589 households |
| Populationsecondyear: | 1070s or 1080s |
| Membership Title1: | Circuit |
Baizhou or Bai Prefecture was a zhou (prefecture) in imperial China in modern southern Guangxi, China. It existed intermittently from 623 to 1136, and between 742 and 758 it was known as Nanchang Commandery.
Bai Prefecture administered the following counties (縣) through history:
Nanchang, Jianning, and Zhouluo, all abolished by the Song dynasty in 972, are probably all in modern Bobai County.