The Caucasian languages are those languages of the Caucasus area which do not belong to any of the major language families also found elsewhere. There are three distinct families of Caucasian languages:
- Northwest Caucasian, 5 languages of which one is now extinct
- Northeast Caucasian, 29 languages
- Kartvelian (South Caucasian), 4 languages
None of these three families could so far be shown to be related to any other language or language family; they are not even related among each other. The three families are also typologically quite different, with Northwest Caucasian showing a strong head-marking profile while the Northeast Caucasian languages are strongly dependent-marking, and the Kartvelian languages in between. Yet, common features of the Caucasian languages are rich consonant inventories with uvulars, ejectives and at least two series of sibilants; a rich inflectional morphology; and ergativity.