Social innovation (SI) has, in the last decade or so, become an important idea and concept in policy, practice and scholarship surrounding human development. It is often seen as an antidote to narrowly defined technological and market-oriented modes of innovation. Its historical significance and development, tied to centuries of struggles for social change, remain under-appreciated and unacknowledged. This Advanced Introduction explores the historical and contemporary meanings of social innovation and its relationship with political and social movements. It develops an understanding of SI as a form of ethical practice for meeting needs, transforming social relations, and collectively empowering communities to shape the future. Additionally, it proposes that ethical research should aim to be socially innovative in this sense and provides concrete suggestions of how this concern can be embodied in action-research and community development methodologies.