Diabetes mellitus and hypertension are major cardiometabolic conditions requiring sustained self-management, in which social support from family and peers may facilitate adherence and improve clinical outcomes. However, evidence on the characteristics and implementation of these support interventions remains fragmented. This scoping review aimed to map peer and family support interventions for cardiometabolic management among adults with diabetes mellitus and/or hypertension. A scoping review was conducted following the Arksey and O’Malley framework, with refinements by Levac et al., and reported according to PRISMA-ScR. Literature published in English from 2021 to 2026 was searched in PubMed, Scopus, Web of Science, CINAHL, and Google Scholar. Eligible studies involved adults with diabetes mellitus and/or hypertension and evaluated peer, family, or combined support interventions targeting cardiometabolic management. Data were synthesized descriptively and narratively. Methodological quality was assessed using the appropriate Joanna Briggs Institute (JBI) critical appraisal tools. Nine studies were included, comprising randomized controlled trials, quasi-experimental studies, and a single-arm interventional study. Five studies were conducted in Indonesia, with others from China, the United States, Iran, and India. Interventions included family self-management programs, health coaching, family empowerment, telenursing, patient-family partnerships, peer support, and community-based education. Reported outcomes included improved glycemic control, blood pressure control, self-management, dietary and sodium adherence, medication adherence, treatment compliance, patient-family engagement, self-care, and quality of life. JBI appraisal scores ranged from 76.9% to 100%. Peer and family support interventions demonstrate potential to improve both clinical and behavioral outcomes in adults with diabetes mellitus and/or hypertension. Their integration into community and healthcare-based cardiometabolic management may strengthen sustained self-management and treatment adherence.