Cities can take an active role in creating enablers, such as open innovation platforms, living labs to enhance innovations that can contribute to solving sustainability challenges. In this conceptual paper, we introduce a new governance model, the Circle of Mediators, to facilitate the birth and activities of multi-stakeholder teams to innovate and create solutions. We aim to contribute to discussions on multi- stakeholder governance, sustainability is seen as the context that forces cities to engage in such activities due to the complex nature of global challenges and need for (interdisciplinary or even) transdisciplinary and multi-stakeholder competencies to solve these challenges. The Circle of Mediators orchestrates the establishment of open innovation ecosystems and their innovation co-creation, experimentation and adoption activities, thus making cities and communities inclusive, resilient and sustainable, in accordance with the UN SDG 11 (United Nations 2015). The focus is on the new governance model looked at from mediating and living lab perspectives and experiments with two Finnish cities and sponsored by the EU Cohesion Six City Strategy project. The paper’s contribution builds on the development of the conceptualisation of the new Circle of Mediators model and the identification of research and an action path for both researchers, managers as well as policymakers.