Language revitalization, also referred to as language revival or reversing language shift, is the attempt by interested parties to halt or reverse the decline of a language or to revive an extinct one. Those involved can include parties such as linguists, cultural or community groups, or governments. Often with multiple parties work together on the same project. Languages that may be targeted for language revitalization include those in which the use and prominence is severely limited, called endangered or weakening, or those which have only a few elderly speakers and seem to be dying, called moribund. Sometimes various tactics of language revitalization can even be used to try and revive extinct languages. Though the goals of language revitalization vary greatly from case to case, they typically involve attempting to expand the number of speakers and the use of a language or to maintain the current level in order to protect the language from extinction or language death.

Language revitalization is often deemed necessary because of the sheer amount of linguistic diversity that is being lost. In recent times alone, it is estimated that more than 2000 languages have already become extinct around the world. The UN estimates that more than half of the languages spoken today have fewer than 10,000 speakers and that a quarter have fewer than 1,000 speakers and that, unless there are some efforts to maintain them, over the next hundred years most of these will become extinct. Besides linguistic diversity, issues of culture and identity are prominent reasons why interested parties push for language revitalization. Many people hold the view that languages are unique "cultural treasures. " A community's language is a unique part of their culture, often connecting them with their ancestors or with the land, making up an essential part of their history and how they see themselves.

Language revitalization is also closely tied to the linguistic field of language documentation. In this field, linguists attempt to create full records of a languages grammar, vocabulary, and linguistic features. This practice can often lead to more concern for the revitalization of a specific language on study. Furthermore, the task of documentation is often taken on with the goal of revitalization in mind.