Objectives This study aims to estimate the prevalence, awareness, treatment and control rates of type 2 diabetes (T2D) and pre-diabetes as well as to identify its associated factors among Mongolians living in the Inner Mongolia Autonomous Region, China.Design Cross-sectional study.Setting and participants This sample included 11 361 Mongolian participants from the Inner Mongolian Healthy Aging Intervention Study, a population-based screening project consisting of 141 255 adults aged above 35 years in Inner Mongolia from 2015 to 31 December 2020.Outcome measures The prevalence and 95% CIs of T2D and pre-diabetes were calculated. Factors associated with the prevalence, awareness, treatment and control of T2D were explored by a binomial logistic regression.Results A total of 17.2% (95% CI 16.5% to 17.9%) of the sample had T2D, of whom 34.0% (95% CI 31.9% to 36.1%) were aware of their diagnosis, 24.7% (95% CI 22.8% to 26.6%) were taking prescribed antidiabetic medications, 6.7% (95% CI 5.6% to 7.8%) had achieved control and 27.5% (95 % CI 26.7% to 28.3%) had pre-diabetes. The prevalence of T2D increased with increasing age, male, lower education level, smoking, obesity and a history of hypertension or dyslipidaemia (all p