Doyayo (ethnonym: Dowayo) is a language of the Duru branch of Adamawa languages spoken in Cameroon.

Doyayo (Doo²³ya̰a̰¹yɔ¹ 'man's mouth'; alternatively Doo²waa²³ya̰a̰¹yɔ¹ 'man's child's mouth') is spoken by the Dowayo (or Doo²waa²³yɔ¹ 'man's child') ethnic group.

According to ALCAM (2012), Doayo, which has 18,000 speakers, is the main language of the northern part of Poli commune (in Faro department, Northern Region).^[2]

Taara is spoken in the mountains west of Poli, and Marka in the plains further northwest in Tcheboa commune, Bénoué department.^[2]

The term Namchi, which means "crushed ones" or "those who crush [millet for us]" in Fulfulde, is a cover term that refers not only to the Doayo, but also its neighbors Duupa and Dugun (the latter two are both Dii languages).^[2]

Joseph Greenberg's "Sewe" is in fact a variety of the Doayo language documented by Griaule. The name comes from the informant's village, Sewe.^[2]

Doyayo dialects are:^[3]

• Markɛ (spoken in the northwestern plains)
• Tɛ̰ɛ̰rɛ of Poli
• Southern Tɛ̰ɛ̰rɛ (spoken in the mountains to the south)
• Sewe (Séwé)

(Note that there are two distinct Tɛ̰ɛ̰rɛ dialects.)

Blench (2004) considers the Sewe dialect to be a separate language, no more closely related to Dowayo than to Koma and Vere.