The Balkan sprachbund or linguistic area is the ensemble of areal features—similarity in grammar, syntax, vocabulary and phonology—among the languages of the Balkans. Several features are found across these languages though not all need apply to every single language. The languages in question may be wholly unrelated as modern forms in that they belong to various branches of Indo-European (such as Slavic, Greek, Romance, Albanian and Indo-Aryan) and also outside of Indo-European (such as Turkish). Also interesting is that some of the languages use these features for their standard language (i.e. those whose homeland lies almost entirely within the region) whilst other populations to whom the land is not a cultural pivot (as they have wider communities outside of it) may still adopt the features for their local register; this is turn is viewed as non-standard by their respective peoples away from the region.

While they share little vocabulary, their grammars have very extensive similarities; for example they have similar case systems and verb conjugation systems and have all become more analytic, although to differing degrees.