Aims: While peer support research is growing in the Type 1 diabetes (T1D) community, the peer supporter training (PST) process is rarely documented in detail. This study provides a comprehensive description of PST and evaluation for the REACHOUT mental health support intervention, and examines the feasibility and perceived utility of PST. Methods: Fifty‐three adults with T1D were recruited to participate in a 6‐hour, zoom‐based PST program for mental health support. The program was structured in three parts: (1) internal motivation, resilience and empathy; (2) mindfulness, emotions and diabetes distress; and (3) active listening and deferring clinical questions to professionals. Candidates were evaluated based on eight pre‐established competency criteria during a 5‐day support trial with an assigned standardized T1D participant. Perceived usefulness of training skills was also assessed 3 months into the REACHOUT mental health support intervention. Results: Fifty‐one of the fifty‐three candidates who completed training achieved the criteria to graduate. Mean scores for the eight competency domains were: listens actively (4.55); asks open‐ended questions (4.12); expresses empathy (4.42); avoids passing judgment (4.67); sits with strong emotions (4.44); refrains from giving advice (4.38); makes reflections (4.5); and defers medical questions (4.58). Of the skills learned during the PST, 95% rated interpreting and discussing diabetes distress profile and expressing empathy as moderately to extremely useful. Conclusions: Findings demonstrate that it is feasible to recruit and graduate the number of trainees needed using a rigorous process. Only by making training protocols available can the PST be replicated and translated to other T1D populations (e.g. adolescents, parents of children with T1D). [ABSTRACT FROM AUTHOR]