The European Commission has invited the Technopolis Group, the Oxford Internet Institute (OII) and the Centre for European Policy Studies (CEPS) to conduct an international study on innovative data-driven approaches to inform policymaking. In short: data for policy. The main objective of the study was to explore the opportunities that innovative data-driven approaches offer for evidence-informed policy making, including the relevant data sources and technologies. The focus of the study was on (big) data for policy opportunities for national and international policy makers, including the European Commission itself. While exploring big data, linked data and innovative uses of small data across the policy cycle, the study touched on open data, citizen science, participative policymaking and advances in system dynamics. The study was action-driven and aimed at the development of an Agenda for action for practitioners and other stakeholders (policymakers, public agencies, NGOs, companies that provide tools, collect data, etc.). To this end, it engaged with interested parties and contributed to creating or linking relevant communities in the field. For instance, the draft report about the State-of-the-Art was published on the study website www.data4policy.eu allowing stakeholders to provide comments and suggest relevant initiatives. Moreover, the draft report about the State-of-the-Art was presented and discussed at the Big Data for Policy conference that was held 15-17 June 2015 in Cambridge. The study workshop took place 22 September 2016 in Brussels. The workshop was designed as an interactive event that attracted over 90 practitioners and other stakeholders.