Research on social innovation has gained momentum over the last decade, spurred notably by the growing interest in social issues related to policy making, public management and entrepreneurship in response to the grand challenges societies in Europe and worldwide face. Accelerated by the normative turn in research and innovation policies towards ‘missions’, social innovation is nowadays a central element on policy agendas, from the urban and regional level to the national and subnational level of the European Commission and the OECD. However, for social innovations to unfold their full potential a better understanding of underlying mechanisms, processes and impacts is necessary. The first three chapters focus on framework conditions and characteristics of social innovation. The following two chapters emphasise the determinants of social innovation and translocal empowerment. In the last part, attention is devoted to social innovation in specific fields such as health care and greening society, and social innovations’ transformative potential. The chapters in this book were originally published as a special issue of the journal,