The European Commission’s Knowledge Centre on Migration and Demography (KCMD) and the IOM's Global Migration Data Analysis Centre (GMDAC) organise the workshop on Big Data and alternative data sources on migration: from case studies to policy support. Researchers, data holders/providers, policymakers and practitioners will gather to: i. Review latest concrete and innovative applications of big data and alternative data sources for a better understanding of migration-related phenomena, and practical examples of use for policymakers; ii. Identify the most promising applications of big data and alternative sources to complement and enrich traditional data on migration; iii. Discuss possibilities, obstacles, and requirements for more systematic use of big data in the field of migration, and for increased collaboration between researchers, data providers and policymakers; iv. Suggest pragmatic follow-up steps to expand use of such data sources in support of migration policymaking.