The Mixtec languages, or dialect cluster, belong to Otomanguean language family of Mexico, and are closely related to the Trique and Cuicatec languages. They are spoken by over half a million people. Identifying how many Mixtec languages there are in this complex dialect continuum poses challenges at the level of linguistic theory. Depending on the criteria for distinguishing dialects from languages, there may be as many as fifty Mixtec languages.

The name "Mixtec" is a Nahuatl exonym, from [miʃ] 'cloud' [teka] 'inhabitant of place of'. Speakers of Mixtec use an expression (which varies by dialect) to refer to their own language, and generally this expression means "word of the rain": Tu'un Sávi [tũˀũ saβi] in one variety, for example, and Dà'àn Dávi [ðãˀã ðaβi] in another.

The Mixtec language group belongs to the Otomanguean family, whose urheimat may be the valley of Tehuacán (Puebla). This site was one of the places of the domestication of maize. The thousand-year presence of Otomanguean-speaking groups in this region makes it probable that they were active in this domestication process, which favored the inhabitants of the Altiplano's transition to a sedentary lifestyle and thus influenced the development of Mesoamerican civilization. Campbell and Kaufman have proposed that the Otomanguean languages began to diverge about 1500 BCE. The difficulty of establishing more general relationships between the eight subgroups of the family presents a difficulty for making more detailed inferences on the historical development of the languages.