Abstract Background Black men are more likely to be diagnosed with type 2 diabetes (T2D) compared to non-Hispanic White men, and this disparity increases among men over the age of 55. A growing body of literature demonstrates the critical role of gender in the management of health behaviors such as T2D and shows that male gender norms can conflict with healthy behaviors. These studies suggest that tailoring diabetes self-management interventions to address the needs of Black men may be critical to helping them to achieve optimal health outcomes. Further, our own research on Blacks with T2D found gender disparities in participation in diabetes interventions, with males participating at significantly lower rates than females. Peer leaders are trained lay individuals who are used to provide ongoing diabetes self-management support to people with diabetes, particularly in minority communities. However, despite studies showing that diabetes management interventions using peer leaders have been successful, the majority of peer leaders as well as the participants in those studies are women. The limited studies to date suggest that Black men with T2D prefer peer-led, male-to-male T2D programs, however, this research consists primarily of nonrandomized, small sample feasibility studies calling for additional studies to establish the efficacy of these approaches. The proposed study will develop and preliminarily validate the effectiveness of an adapted peer leader diabetes self-management support (PLDSMS) intervention designed to improve diabetes-related lifestyle and self-management behaviors in Black men (over 55) with T2D. Method We propose to tailor an existing intervention by 1) our using male peers and 2) modifying the peer leader training content to focus on material appropriate for men. The proposed study includes a developmental phase (development of the intervention with expert feedback, followed by feasibility testing with Black men) and a validation phase [randomized clinical trial (RCT)]. Discussion If successful, this study will lead to the development and dissemination of an intervention that will address the unique needs of Black men with T2D, helping them to achieve optimal diabetes self-management and health outcomes. Trial registration Registered at ClinicalTrials.gov with an ID NCT04760444 on February 17, 2021