This chapter focuses on multilingualism as an important facet of contemporary digital social media practices. It shows how the affordances of digital spaces and the fluidity of varied linguistic and semiotic resources can give people much-desired freedom and agency, lowering the boundaries between the Global South and Global North, while they can also serve as a powerful means for the reproduction of violence, intolerance and injustice. The argument is made that the study of digital multilingualism calls for multi-layered and nuanced analyses of the diverse multimodal, language and cultural resources drawn on and taken up in digital practices, as well as of their social, cultural, historical, political and ideological associations. The chapter first discusses specific paradigmatic approaches to digital multilingualism: multilingualism as linguistic heterogeneity, as translinguality and as discourse practice. In addition, implications of digital multilingualism for identity work, normativity, moral panics and hate discourses, nationalist, monolingual, monocultural and mono-religious discourses as well as for language learning and teaching are identified. The chapter ends with a discussion of future challenges for the study of digital multilingualism.