The growth-oriented, fossil-based energy system oftoday is undergoing a transformation towards renewable energies. However, a mere switchin technologies, without a thorough examination of underlying socio-economic relationsand power structures, risks perpetuating the same crises of inequality and ecological degradationof the previous system. It follows then that a transformation in the energy system is required whichenhances both social and ecological sustainability. The present research weaves togethertransformations and post-growth literature and constructs a qualitative analytical frameworkagainst which an initiative’s post-growth transformative capacity can be tested. It then zoomsback in to empirically test the framework on energy communities in Greece. Results show that Greekenergy communities hold significant post-growth transformative capacity, in areas suchas networking, actor empowerment and innovative learning, shared vision creation, alterationof resource flows and a reconfiguration of ownership and governance structures. The researchconcludes with some policy recommendations that could enhance the post-growthtransformative capacity of Greek energy communities, such as the creation of a national federationof energy communities. The post-growth transformative capacity framework presentedin this research could be used as a descriptive starting point, from which academics orpractitioners can build on to explore post-growth futures and post-growth transformativecapacity in other sectors (e.g., food or transportation) and contexts (e.g., Global South countries).