This paper explores the contribution of knowledge intermediation to sustainability transitions and digitalization. Currently, there is a gap in the literature concerning the understanding of knowledge intermediation and transition intermediation, even though the systemic coaction of different intermediaries is essential for policy making. We use an explorative qualitative approach based on interviews with German knowledge intermediaries. We find three functions of knowledge intermediation that proactively contribute to socio-technical transitions: (i) information dissemination via events, (ii) knowledge exchange via network building, and (iii) implementation support via consulting. Thereby, we reveal an increasingly active role of knowledge intermediation in regional transitions. We identify additional roles concerning the identification and monitoring of new projects that emerge from the effects of digitalization on sustainability. We contribute to the current scholarly discussion about knowledge intermediation by complementing its’ contributions to innovation and regional development by proactive contributions to transition processes.