Background: Diabetes has far-reaching negative impacts on the biological, physiological and psychosocial health of people living with the disease and their families, placing a heavy burden on health systems worldwide. Self-management education and support have a critical role to play but are insufficiently used. Therefore, there is a need to develop and implement effective support interventions for this population. Methods: This study protocol comprises the development and feasibility testing phases of a virtual nursing intervention named PIAVIR (Pratique infirmière avancée virtuelle – Virtual advanced nursing practice), using the Medical Research Council framework for developing complex interventions. PIAVIR is based on humanistic-centred theories of education: adult learning theory, experiential learning and transformative learning, as well as the results from focus group interviews with healthcare professionals and people with type 1 or type 2 diabetes. The feasibility testing will include 60 participants recruited and randomised to either the intervention group with immediate access to the intervention for 6 months or to the waiting-list control group with access to the intervention after a 6-month waiting time. Both groups will be followed-up for another 6 months post-intervention. Outcome measures will be collected at baseline, 6 months and 12 months. Findings will be evaluated against predetermined feasibility criteria and changes in metabolic and psychosocial outcomes. Results: This paper presents the study protocol and describes and discusses the development and feasibility phases of the PIAVIR virtual intervention. The results of the feasibility study cover primarily: acceptability, feasibility, recruitment and completion of the newly developed intervention, as well as metabolic and psychosocial measures. Conclusion: This study contributes to the development of effective virtual self-management education and support interventions and informs a larger randomised controlled trial to examine the effectiveness of the intervention in different populations and multiple sites. Ethics and dissemination: This study has ethical approval from the Research Ethics Committees of Canton Vaud (CER-VD-2021-01763). The results will be disseminated to professional and lay audiences. Trial registration number: International Standard Randomized Controlled Trial Number registry ISRCTN30640743.