This chapter introduces the concept of migrant digital space (MDS). MDS is defined as configured by migrants’ online activity before the journey, en route, and when settling down, and as a space shaped by practices. Following a relational approach to space, MDS is understood as an outcome of social relations and practices with material and intangible characteristics. Within this perspective, MDS is formed by (a) digital subjects (accounts, pages, hashtags, channels), (b) migrant-related topics (such as discussions on migration routes; language lessons; football conversations; university enrolment; job seeking) through conversations across (c) various digital platforms. After introducing the concept of MDS it is explained how, in the context of the DIGINAUTS project, the concept was developed into the collection of a dataset of public Facebook content, which was subsequently implemented. The data collected and some of its characteristics are highlighted.