Tai Yo (Vietnamese spelling: Tai Do) is a Tai language of Southeast Asia. It is closely related to Tai Pao of Vietnam, where it may have originated. It was once written in its own script, but that is no longer in use. The language is known regionally as Tai Do and Tai Quy Chau in Vietnam, and as Tai Mène and Tai Nyaw in Thailand, Laos, and Cambodia.