Chiềng Sơ is a commune in Sơn La province, Vietnam.
History Chiềng Sơ commune formerly belonged to Sông Mã district, Sơn La province.
On 16 June 2025:
The National Assembly of Vietnam adopted Resolution No. 203/2025/QH15 amending and supplementing several articles of the Constitution of the Socialist Republic of Vietnam. The resolution provided for the cessation of district-level administrative units nationwide from 1 July 2025. The Standing Committee of the National Assembly of Vietnam adopted Resolution No. 1681/NQ-UBTVQH15 on the reorganization of commune-level administrative units in Sơn La province in 2025. Under the resolution, the entire natural area and population of Yên Hưng and Chiềng Sơ communes were consolidated to form a new commune named Chiềng Sơ. The resolution took effect on 16 June 2025. References