Crowdfunding presents many opportunities for moving towards a sustainable society, with specific interest for sustainable entrepreneurs and innovators. In order to examine the potential role of crowdfunding in this context, we position this Special Issue (SI) within the larger stream of sustainability transitions literature, and in particular in relation to one of the field's key frameworks, i.e. the Multi-Level Perspective (MLP). We argue that crowdfunding represents a novel socio-technical practice with the potential of upscaling and transforming financial and – potentially – sustainability regimes. This introductory article contains an overview of the articles, described by using the MLP typology. Some authors describe the role of crowdfunding in enabling user-producer and user-consumer interaction at an early stage; others focus on crowdfunding as a tool for user-legitimators and user-citizens. In terms of future research, the novelty of the phenomenon leaves a wide range of areas open for further research, with the current literature primarily focused on uncovering the antecedents of funding success and failure, something that is also apparent in this SI. To help the field move forward, we identify five areas as the most relevant for future research.