Health systems across the world face multiple pressures. Input costs are soaring, systems are struggling to keep-up with increasing demand for their services and areas of the world still lack universal health coverage. All of this whilst health inequalities between the best and worst-off within countries persist and, in some countries, are even widening. There is a need to think of new initiatives in response to these global health challenges. One such response is social finance. Social finance is about creating social returns. This innovative and rapidly growing sector promotes new ways of banking and funding social and public services. However, social finance has an underrecognised, and potentially underexploited, role in responding to specific aspects of global health challenges: funding and facilitating access to health (care) services and acting on health. The objectives of this book are to conceptualise and evidence different forms of social finance - microfinance and impact bonds - acting in these ways and to critically engage with current debates and challenges. With such evidence to hand, we can either avoid adoption of new trends in financing public services or, more hopefully, attract greater policy support and resources for new tools for public health and in supporting more precarious, but potentially essential, parts of the finance sector. This book will be essential reading to students, researchers, policymakers and the general public alike who are interested in, or who work in, and across, health systems and social finance.