Tai Muong Vat (Vietnamese: Tiếng Thái Mường Vạt) is a Southwestern Tai language spoken in Yên Châu District, Sơn La Province, northwestern Vietnam.
Theraphan's (2003) Tai Muong Vat data was collected in the following 2 villages.
This was first noted by Chamberlain (1984), who suggests that it may be more closely related to the Tai Neua variety of Xieng Kho, Laos than to Tai Dam of Son La, Vietnam.
Tai Dam is the dominant language in Yên Châu, while Ksingmul, a Khmuic language, is also spoken in both Yên Châu and Xieng Kho.
As a result, the Tai Muong Vat and Ksingmul share many cultural customs with the Tai Dam, and have similar ethnic dress as well (Theraphan 2003).