Background <p>Loneliness is more pronounced in individuals with diabetes; however, limited studies have investigated loneliness and its risk factors. This study estimated the pooled prevalence of loneliness and identified its risk factors in individuals with diabetes.</p> Methods <p>A systematic review and meta-analysis of observational studies was conducted. CINAHL, Cochrane, Embase, PubMed, Scopus, and Web of Science databases were searched from their inception to September 22, 2023. We systematically searched and analyzed 10 studies involving 6036 individuals with diabetes to determine the pooled prevalence of loneliness. Five studies provided information on risk factors. Using a random-effects model, we calculated prevalence rates and odds ratios with 95% confidence intervals.</p> Results <p>The overall prevalence of loneliness was 31.1% and severe loneliness was 4.6%. White race, lower education level, middle income, low income, longer diabetes duration, lower cognitive function, living alone, previous loneliness experience, and depression were identified as significant risk factors for loneliness in individuals with diabetes.</p> Conclusion <p>Over 30% of individuals with diabetes experience loneliness. Several sociodemographic factors, low cognitive function, and depression are risk factors for loneliness.</p>