语言联盟（德语：Sprachbund；英语：Sprachbund, linguistic convergence；俄语：языковой союз），也称语言区域、语言的区域分类，指没有亲属关系的语言，由于长期共处于一个地区而在语言结构上产生共同区域特征的现象。语言联盟中的不同语言，词汇上相互有大量的借贷，而且语音、语法系统有着一些共同的结构格局、结构规则，这不是因为这些语言同源，在发展的过程中留存了历史上的同一语言的特征，而是语言长期密切接触的结果。但语言联盟中的诸民族，在经济、文化、人口比例上相差不很悬殊，因此还能保持各自语言的本质，相当多的核心词根继承了自己语言的祖语。

A sprachbund (/ˈsprɑːkbʊnd/; German:[ˈʃpʁaːxbʊnt], "federation of languages") – also known as a linguistic area, area of linguistic convergence, diffusion area or language crossroads – is a group of languages that have common features resulting from geographical proximity and language contact. They may be genetically unrelated, or only distantly related. Where genetic affiliations are unclear, the sprachbund characteristics might give a false appearance of relatedness. Areal features are common features of a group of languages in a sprachbund.