We compared the risk of diabetes in 48,299 psychiatrically ill youth. Of 7,253 youth exposed to antipsychotics, 52 (0.72%; 95% CI = 0.52% - 0.91%) developed type 2 diabetes. Of 41,046 youth without exposure to antipsychotics, 111 (0.27%; 95% CI = 0.22% - 0.32%) developed type 2 diabetes. In a 25,033 + 16,013 logistic regression analysis, type 2 diabetes development was associated with antipsychotic drug exposure (odds ratio [OR] = 1.60; 95% CI = 1.08 - 2.36, p < .05) female sex, (OR = 4.48; 95% CI = 2.90 - 6.91, p < 0.001) and older age at first psychiatric diagnosis (OR = 1.19; 95% CI = 1.12 - 1.27, p < 0.001), but not with psychiatric diagnosis. In a Cox-regression analysis, shorter time to type 2 diabetes onset was associated with female sex (Hazard Ratio (HR) = 4.83; 95% CI = 3.05–7.66, p = 0.001), and older age at first psychiatric diagnosis (HR = 1.19; 95% CI = 1.12-1.28, p = 0.001), while antipsychotic exposure (HR) = 1.41; 95% CI = 0.92-2.16, p = 0.11) trended towards increasing the rate of diabetes.