Yao is a Bantu language in Africa with approximately 1 million speakers in Malawi, half a million in Tanzania, and around 450,000 in Mozambique. A block of Yao-speaking country that straddles the Mozambique - Tanzania border is separated from Lake Malawi by a mainly Nyanja-speaking area. There are also some speakers in Zambia. In Malawi, the main dialect is Mangoche, mostly spoken around Lake Malawi. In Mozambique, the main dialects are Makale and Massaninga. The language has also gone by several other names in English, including ChiYao or CiYao (the prefixed form), Achawa, Adsawa, Adsoa, Ajawa, Ayawa, Ayo, Ayao, Djao, Haiao, Hiao, Hyao, Jao, Veiao, and WaJao.

Comparison with the Mwera language suggests that the two languages are very similar.

In common with very many vernacular languages in Africa, it has historically enjoyed little official recognition and literary work in the region where Yao is spoken has taken place in such languages as Arabic, English, German and Portuguese.

As in English, unvoiced plosives are breathed and voiced plosives are not. There are conventionally only five 'pure' vowels, viz. a, e, i, o, u, though there is some variation in vowel length. Yao is minimally tonal language, as is common in Bantu languages.