The Cubeo language (also spelled Cuveo) is the language spoken by the Cubeo people in the Vaupés Department, the Cuduyari and Querarí Rivers and their tributaries in Colombia, and in Brazil and Venezuela. It is a member of the central branch of the Tucanoan languages. Cubeo has borrowed a number of words from the Nadahup languages, and its grammar has apparently been influenced by Arawak languages. The language has been variously described as having a subject–object–verb or an object–verb–subject word order, the latter very rare cross-linguistically. It is sometimes called Pamiwa, the ethnic group's autonym, but it is not to be confused with the Pamigua language, sometimes called Pamiwa.

Đ is used in its bowl-struck form, approximately ⟨d̶⟩.

There are six oral vowels and six nasal vowels. /ɨ/ is pronounced as in roses.

Unusually, Cubeo has a velar fricative /x/ but no strident fricative /s/. When older Cubeos use Spanish loans with /s/, they pronounce it as /tʃ/ before vowels. The /s/ deletes in word-final position in loans as in [xeˈtʃu] < Sp. Jesús [xeˈsus] 'Jesus' (cf. Colombian Spanish [heˈsus]).

The stressed syllable is the first syllable with high tone in the phonological word (usually the second syllable of the word). Stress (and by extension, the position of the first high-tone syllable) is contrastive.

Most morphemes belong to one of three categories:

No root is unmarked with respect to this nasal/oral division, but some roots are partially oral and nasal, /bãˈkaxa-/ [mãˈkaxa-] 'to defecate'.

Suffixes that begin with consonants without nasal allophones may be only nasal or oral, not unmarked, but suffixes that begin with consonants that have nasal allophones (/b, d, j, w, x, r/) may belong to any of the three classes above. It is impossible to predict the class to which a nasalizable consonant-initial suffix may belong.