These three datasets support the findings of the paper "Open Data Intermediaries in Developing Countries" published in the Journal of Community Informatics. The paper explores the concept of open data intermediaries using the theoretical framework of Bourdieu’s social model, particularly his species of capital. Secondary data on intermediaries from Emerging Impacts of Open Data in Developing Countries research was analysed according to a working definition of an open data intermediary presented in this paper, and with a focus on how intermediaries are able to link agents in an open data supply chain, including to grassroots communities. The study found that open data supply chains may comprise multiple intermediaries and that multiple forms of capital may be required to connect the supply and use of open data. The effectiveness of intermediaries can be attributed to their proximity to data suppliers or users, and proximity can be expressed as a function of the type of capital that an intermediary possesses. However, because no single intermediary necessarily has all the capital available to link effectively to all sources of power in a field, multiple intermediaries with complementary configurations of capital are more likely to connect between power nexuses. This study concludes that consideration needs to be given to the presence of multiple intermediaries in an open data ecosystem, each of whom may possess different forms of capital to enable the use of open data. Data: Data for 27 Asian cases extracted from the 17 Emerging Impacts of Open Data in Developing Countries case study reports. Data for 4 African cases extracted from the 17 Emerging Impacts of Open Data in Developing Countries case study reports. Tabulated data of findings for types of capital, organisational type and primary source of revenue for each of the 32 open data intermediaries included in the study.