Foreign direct investment (FDI) is becoming increasingly critical to the economies of developing countries, in part due to a major expansion in the scope of global value chains (GVCs), whereby lead firms outsource parts of their production and services activities across complex international networks. While FDI delivers a number of important contributions in terms of investment, employment, and foreign exchange, it is its spillover potential - the productivity gain resulting from the diffusion of knowledge and technology from foreign investors to local firms and workers - that is perhaps the most valuable contribution to long run growth and development. While substantial research has been undertaken on the existence and direction of spillovers from FDI, many questions remain. Moreover, there is a need to understand better the dynamics of spillovers in certain contexts, including: i) in low income countries, especially in Sub-Saharan Africa; ii) outside of manufacturing sectors (especially resource-based sectors); and, iii) in the context of GVCs. This book presents the results of a groundbreaking designed to address these issues drawing on detailed field research in eight countries (including five in Sub-Saharan Africa) over three sectors: agribusiness, apparel, and mining. The book presents a summary of the results of this analytical work and discusses their implications for policymakers hoping to harness the power of FDI for greater development outcomes.