This article examines the importance of language in international migration from multiple angles by studying the role of linguistic proximity, widely spoken languages, linguistic enclaves and language-based immigration policy requirements. To this aim we collect a unique data set on immigration flows and stocks in 30 OECD destinations from all world countries over the period 1980–2010 and construct a set of linguistic proximity measures. Migration rates increase with linguistic proximity and with English at destination. Softer linguistic requirements for naturalisation and larger linguistic communities at destination encourage more migrants to move. Linguistic proximity matters less when local linguistic networks are larger.