Governments are increasingly making their data available online in standard formats and under licenses that permit the free re-use of data. The justifications advanced for this include claims regarding the economic potential of open government data (OGD), the potential for OGD to promote transparency and accountability of government and the role of OGD in supporting the reform and reshaping of public services. This paper takes a pragmatic mixed-methods approach to exploring uses of data from the UK national open government data portal, data.gov.uk, and identifies how the emerging practices of OGD use are developing. It sets out five ‘processes’ of data use, and describes a series of embedded cases of education OGD use, and use of public-spending OGD. Drawing upon quantitative and qualitative data it presents an outline account of the motivations driving different individuals to engage with open government data, and it identifies a range of connections between open government data use of processes of civic change. It argues that a “data for developers” narrative that assumes OGD use will primarily be mediated by technology developers is misplaced, and that whilst innovation-based routes to OGD-driven public sector reform are evident, the relationship between OGD and democracy is less clear. As strategic research it highlights a number of emerging policy issues for developing OGD provision and use, and makes a contribution towards theoretical understandings of OGD use in practice.