Enosis (Greek: Ένωσις, IPA: [ˈenosis], "union") is the movement of various Greek communities that live outside Greece for incorporation of the regions that they inhabit into the Greek state. The idea is related to the Megali Idea, an irredentist concept of a Greek state that dominated Greek politics following the creation of modern Greece in 1830. The Megali Idea called for the annexation of all ethnic Greek lands, parts of which had participated in the Greek War of Independence in the 1820s but were unsuccessful and so remained under foreign rule.

A widely known example of enosis is the movement within Greek Cypriots for a union of Cyprus with Greece. The idea of enosis in British-ruled Cyprus became associated with the campaign for Cypriot self-determination, especially among the island's Greek Cypriot majority. However, many Turkish Cypriots opposed enosis without taksim, the partitioning of the island between Greek Cypriots and Turkish Cypriots. In 1960, the Republic of Cyprus was born, resulting in neither enosis nor taksim.

Around then, Cypriot intercommunal violence occurred in response to the different objectives, and the continuing desire for enosis resulted in the 1974 Cypriot coup d'état in an attempt to achieve it. It, however, prompted Turkey into launching the Turkish invasion of Cyprus, which led to partition and the current Cyprus dispute.