It is widely acknowledged that Higher Education Institutions (HEIs) should go beyond their traditional education and research functions and also be key actors in promoting, creating and sustaining social innovation that responds to multifaceted challenges. Social innovation has gained relevance within the framework of academia at the international level, although is recognised the need to enable social innovation ecosystems across Europe through the adoption of systemic solutions, involving diverse actors, institutions, and places, involving all-kind of social innovation actors (social innovation actors/social entrepreneurs, SMEs, start-ups, accelerators and business incubators, investors, industry, foundations, philanthropy societies, HEIs and RTOs public-owned enterprises). Hence, Innovation Nexus starts from a clear commitment from the participating HEIs to balance the fourth helix by increasing the role of HEIs as drivers of social innovation, but in co-construction with other stakeholders from across the fourth helix. Specifically, a methodology consisting of two distinct (but complementary) phases has been defined. In the first phase, the focus will be on innovation actors and on building capacity among them, so that they become better equipped to work with social entrepreneurs; in the second phase, the focus will be on social innovation actors and on their access to the resources of innovation ecosystems.