An official language is a language that is given a special legal status in a particular country, state, or other jurisdiction. Typically a nation's official language will be the one used in that nation's courts, parliament and administration. However, official status can also be used to give a language (often indigenous) a legal status, even if that language is not widely spoken. For example, in New Zealand the Māori language has official status under the Māori Language Act 1987 even though it is spoken by less than five percent of the New Zealand population. Non-national or supra-national organizations such as the United Nations and the European Union may also have official languages.

Official language status is often connected with wider political issues of sovereignty, cultural nationalism, and the rights of indigenous peoples and ethnic minorities, including immigrant communities.

For example, the campaign to make English the de jure official language of various states in the United States of America is often seen as a way of marginalizing non English-speaking minorities, particularly Hispanic and Latino Americans, while others see it as a unifying force among numerous immigrant groups. In the Republic of Ireland the decision to make the Irish language an official language was part of a wider program of cultural revitalization, de-anglicisation and Gaelic nationalism following centuries of English rule in Ireland. Despite its status as an official language, Irish has been reduced to a minority language in Ireland as a result of English rule, as is the case in North and South America where various indigenous languages have been replaced by that of the colonists. Various indigenous rights movements have sought greater recognition of their languages, often through official language status.