The paper analyses the role of universities as key actors in the green transition ecosystem, focusing on the interface between smart cities, urban management and different stakeholders. From a multi-level governance perspective, universities are approached as nodes of knowledge, innovation and policy co-creation, capable of integrating the objectives of decarbonisation, urban resilience and digitalisation into local development strategies. The study examines three main dimensions: (1) the university as a provider of scientific expertise and data for smart urban planning; (2) the university as a facilitator of green innovation and technology transfer, through urban living labs, innovation hubs and public–private partnerships; and (3) the university as a normative and educational actor, forming green and digital competences for local administrations, businesses and citizens. In the cities included in the European mission "100 climate neutral cities", local universities provide expertise for energy transition plans, decarbonization scenario assessments and green mobility solutions. In addition, in Romania, universities participate in national platforms and initiatives such as "The Future of Energy", where industry experts and academics contribute to the debate and co-design of policies for the transition to renewable sources alongside the younger generation. Various universities in Romania are involved alongside energy companies in national and European projects aimed at deeply modernizing energy systems through advanced technologies and interdisciplinary solutions regarding smart grids, energy storage, energy-efficient buildings and the digitalization of energy systems. The methodology combines conceptual and policy analysis with case studies on university initiatives integrated into smart city strategies and local climate action plans. The results highlight that universities can function as orchestrators of the green transition ecosystem, accelerating the integration of digital and sustainable solutions in urban management, with direct impact on the quality of governance, community participation and environmental performance at the urban level. In this role, universities operate as intermediary institutions that connect local authorities, businesses, civil society and technology providers, facilitating dialogue, co-creation and experimentation around low-carbon, resource-efficient and data-driven urban solutions. By leveraging their research capacities, living labs and interdisciplinary expertise, they help translate climate and digital strategies into concrete pilot projects, decision-support tools and evidence-based policies that can be scaled across the city.