BACKGROUND: This meta-analysis aims to: (i) describe the pooled prevalence of diabetes in people with intellectual disabilities, (ii) investigate the association with demographic, clinical and treatment-related factors and (iii) compare the prevalence versus age- and gender-matched general population controls. METHODS: Pubmed, Embase and CINAHL were searched until 01 May 2021. Random effects meta-analysis and an odds ratio analysis were conducted to compare rates with controls. RESULTS: The trim- and fill-adjusted pooled diabetes prevalence amongst 55,548 individuals with intellectual disabilities (N studies = 33) was 8.5% (95% CI = 7.2%-10.0%). The trim- and fill-adjusted odds for diabetes was 2.46 times higher (95% CI = 1.89-3.21) (n = 42,684) versus controls (n = 4,177,550). Older age (R2  = .83, p < .001), smoking (R2  = .30, p = .009) and co-morbid depression (R2  = .18, p = .04), anxiety (R2  = .97, p < .001), and hypertension (R2  = 0.29, p < .001) were associated with higher diabetes prevalence rates. CONCLUSIONS: Our findings demonstrate that people with intellectual disabilities are at an increased risk of diabetes, and therefore routine screening and multidisciplinary management of diabetes is needed.