This essay analyzes the role of Social Innovation (SI) initiatives in promoting social-ecological transformations and emphasizes the need for political support for such initiatives. Drawing on insights from new institutional theory and democratic theory, the essay presents three key arguments. First, due to their diversity and everyday orientation, SI initiatives serve as critical idea generators for socio-ecological transformations but require resources from actors in their institutional environment for implementation. Second, SI initiatives enhance the democratic legitimacy of socio-ecological transformations but need institutional embeddedness to provide them with the necessary legitimacy to effectively shape society. Finally, SI initiatives are essential in promoting cultural change towards sustainability but need the support of regulators to respond to the urgency of many sustainability issues. The reflections in this paper contribute to a better understanding of the importance of SI initiatives in addressing sustainability challenges, and the implications for future policy initiatives to support them.