This chapter describes how third-party mediated inter-organisational networks may support small-and medium-sized enterprises (SMEs) in overcoming barriers related to sustainability-oriented innovation which stem from disadvantages inherent in the size and type of their organisations. It shows that which additional benefits SMEs can derive from participation in such a network structure. The chapter explains the special role of these actors from the public sector within the network structure. Intermediaries take a central role in inter-organisational networks. Intermediaries are commonly understood as third-party organisations that help to achieve desired objectives. Universities and science partners have been considered as key sources of knowledge in knowledge-based societies. While universities and science partners can be both privately and publicly funded, in many countries they are usually publicly funded, which makes them important public intermediaries. Intermediaries can generally contribute to three different phases: Scanning and recognition; communication and assimilation; and application.