In linguistics, language death occurs when a language loses its last native speaker. By extension, language extinction is when the language is no longer known, including by second-language speakers. Other similar terms include linguicide, the death of a language from natural or political causes, and rarely glottophagy, the absorption or replacement of a minor language by a major language.

Language death is a process in which the level of a speech community's linguistic competence in their language variety decreases, eventually resulting in no native or fluent speakers of the variety. Language death can affect any language form, including dialects. Language death should not be confused with language attrition (also called language loss), which describes the loss of proficiency in a first language of an individual.