This article analyses various International Baccalaureate policy documents to establish whether the International Baccalaureate Diploma Programme has undergone what is described as a multilingual turn. After defining multilingualism and the multilingual turn, it outlines three main implications of what might be considered this paradigm shift for educational policies related to curriculum, pedagogy, and assessment. These implications are used as a framework for the policy analysis to follow, which argues that International Baccalaureate Diploma Programme approaches to language learning are underpinned by a monolingual bias that might delegitimate the knowledge and experience of multilingual learners.