ABSTRACT: In patients with diabetes, psychological well-being constructs (e.g., optimism, positive affect) have been associated with superior medical outcomes, including better glucose control and lower mortality rates. Well-being interventions may be well-suited to individuals with diabetes, as they are simple to deliver, broadly applicable across a range of psychological distress, and may help increase self-efficacy and motivation for diabetes self-care. This systematic review, completed using PRISMA guidelines, examined peer-reviewed studies indexed in PubMed, PsycINFO, and/or Scopus between database inception and October 2017 that investigated the effects of well-being interventions (e.g., positive psychology interventions, mindfulness-based interventions, resilience-based interventions) on psychological and physical health outcomes in individuals with Type 1 or Type 2 diabetes. The search yielded 34 articles (N?=?1635 participants), with substantial variability in intervention type, measures used, and outcomes studied; the majority found the intervention to provide benefit. Overall, results indicate that a range of well-being interventions appear to have promise in improving health outcomes in this population, but the literature does not yet provide definitive data about which specific interventions are most effective. The variability in interventions and outcomes points to a need for further rigorous, controlled, and well-powered studies of specific interventions, with well-accepted, clinically relevant outcome measures.