Yên Bái () was a former city in Vietnam. It was located in the province of Yen Bai, in the north-east region of Vietnam. The city bordered the former districts of Yên Bình District and Trấn Yên District. The city was a settlement along the banks of the Red River, approximately 183 km northwest of Hanoi. It was one of the important trading hubs between the highlands and the lowlands of Northern Vietnam.
At the end of the sixteenth century Yên Bái was a small village in Bach Lam district, Quy Hoa district, Hung Hoa province. On April 11, 1900, Yen Bai province was established by the French colonialist government. The city grew in size with the opening of the HanoiâÂÂLào Cai railway, which attracted many migrants.
On February 10, 1930, part of the 4th Regiment of Tonkinese Rifles stationed at Yen Bai mutinied against their French officers in the Yên Bái mutiny. They were suppressed by loyal troops from the same unit. This incident led to widespread disturbances against French rule across northeastern Vietnam during 1930âÂÂ31.
On July 1, 2025, as per the plan to arrange and merge administrative units in Vietnam, Yên Bái province and Lào Cai province merged to become the new Lào Cai province. In addition to the merge, due to the disestablishment of the "provincial city" tier according to the plan, the capital of Yên Bái province, Yên Bái city was disbanded. The former Yên Bái city was divided into 4 wards: Yên Bái ward, VÃÂn Phú ward, Nam Cðá»Âng ward and ÃÂu Lâu ward.
Yên Bái ward is currently the new capital of the new Lào Cai province.
As of 2019, the city had a population of 100,631, covering an area of 108.15 km<sup>2</sup>.
Yên Bái contained and administered 9 wards and 6 rural communes:
Rural communes: