IntroductionType 2 diabetes is an escalating public health problem closely related to socioeconomic position. There is increased risk of type 2 diabetes in disadvantaged neighbourhoods where education, occupation and income levels are low. Meanwhile, studies show positive health outcomes of participatory community interventions pointing towards the need for increased health promotion and prevention of type 2 diabetes in local communities. This study protocol describes Tingbjerg Changing Diabetes (TCD), a community-based health promotion and type 2 diabetes prevention initiative in Tingbjerg, a disadvantaged neighbourhood in Copenhagen, Denmark.Methods and analysisTCD is a long-term, complex intervention, implemented in three phases from 2014 to 2032, focusing on partnership formation (phase 1, 2014–2019), developing and implementing action for health (phase 2, 2019–2030) and diffusion of knowledge (phase 3, 2022–2032). The Supersetting principles act as guidelines for development and implementation of all intervention activities of TCD, involving several population groups in a variety of everyday life settings. The implementation of TCD draws on Community Action Research design and methodologies. TCD’s evaluation and research strategy is interdisciplinary, pragmatic and multimethod, unfolding at three levels of operation: (A) evaluating activities, (B) researching cross-cutting topics, and (C) researching methods and approaches.Ethics and disseminationTCD has been approved by the Danish Data Protection Agency. Accordingly, the initiative is carried out in adherence to rules and regulations of the Danish Data Protection Agency. As data contain no personal identifiable or sensitive data, no clearance from the Danish National Ethical Review Board can be obtained according to Danish regulations. Citizen, local agents and stakeholders are engaged in the design and execution of TCD to ensure usefulness, reflexive interpretation of data, relevance and iterative progression of interventions. Results will be published in international peer-reviewed scientific journals, presented at conferences and through public media including TCD home page, podcasts and videos.