The concept of a bioeconomy can be understood as an economy where the basic building blocks for materials, chemicals, and energy are derived from renewable biological resources. Biorefineries are considered an integral part of the development toward a future sustainable bioeconomy. The purpose of this literature review is to synthesize current knowledge about how biorefinery technologies are being developed, deployed, and diffused, and to identify actors, networks, and institutions relevant for these processes. Several key findings can be obtained from the literature. First, investing more resources in R&D will not help to enable biorefineries to cross the ‘valley of death’ toward greater commercial investments. Second, while the importance and need for entrepreneurship and the engagement of small and medium-sized enterprises (SMEs) is generally acknowledged, there is no agreement how to facilitate conditions for entrepreneurs and SMEs to enter the field of biorefineries. Third, visions for biorefinery technologies and products have focused very much on biofuels and bioenergy with legislation and regulation playing an instrumental role in creating a market for these products. But there is a clear need to incentivize non-energy products to encourage investments in biorefineries. Finally, policy support for biorefinery developments and products is heavily intertwined with wider discussions around legitimacy and social acceptance. The paper concludes by outlining current knowledge gaps.