IntroductionFoot ulcers are one of the most devastating complications of diabetes mellitus leading to leg amputations. In Canada, systematically marginalised and racialised populations are more prone to developing foot ulcers and at higher risk of limb amputations. Shortages of regulated healthcare have hindered efforts to provide foot care. Upskilling unregulated care providers (UCPs) to deliver foot screening seems a reasonable solution to reduce limb loss. UCPs can advocate for health equity and deliver appropriate care. There is a need, however, to understand how and why an educational intervention for UCPs providing foot screening for these high-risk groups may or may not work.Methods and analysisThis realist review will follow the Realist And Meta-narrative Evidence Syntheses: Evolving Standards standards. First, we will develop an initial programme theory (PrT) based on exploratory searches and discussions with experts and stakeholders. Then, we will search MEDLINE, Embase, PsycINFO, ERIC, CINAHL and Scopus databases along with relevant sources of grey literature. The retrieved articles will be screened for studies focusing on planned educational interventions for UCPs related to diabetic foot assessment. Data regarding contexts, mechanisms and outcomes will be extracted and analysed using a realist analysis through an iterative process that includes data reviewing and consultation with our team. Finally, we will use these results to modify the initial PrT.Ethics and disseminationEthical approval is not required for this review. The main output of this research will be an evidence-based PrT for upskilling programmes for UCPs. We will share our final PrT using text, tables and infographics to summarise our results and draw insights across papers/reports. For academic, clinical, social care and educational audiences, we will produce peer-reviewed journal articles, including those detailing the process and findings of the realist review and establishing our suggestions for effective upskilling programmes.PROSPERO registration numberCRD42022369208.