Objectives To identify risk factors for severe disease and death among patients with diabetes and coronavirus disease 2019 (COVID-19) infection. Methods This retrospective cohort study conducted at three hospitals included 733 consecutive patients with DM admitted with confirmed COVID-19 (March 1 – December 31, 2020). Multivariable logistic regression was performed to identify predictors of severe disease and death. Results The mean age was 67.4 ± 14.3 years, 46.9% were males and 61.5% were African American. Among all patients, 116 (15.8%) died in the hospital. A total of 317 (43.2%) patients developed severe disease, 183 (25%) were admitted to an ICU and 118 (16.1%) required invasive mechanical ventilation. Increasing BMI (OR, 1.13; 95% CI, 1.02–1.25), history of chronic lung disease (OR, 1.49; 95% CI, 1.05–2.10) and increasing time since the last HbA1c test (OR, 1.25; 95% CI, 1.05–1.49) were the preadmission factors associated with increased odds of severe disease. Preadmission use of metformin (OR, 0.67; 95% CI, 0.47–0.95) or GLP-1 agonists (OR, 0.49; 95% CI, 0.27–0.87) was associated with decreased odds of severe disease. Increasing age (OR, 1.21; 95% CI, 1.09–1.34), co-existing chronic kidney disease greater than stage 3 (OR, 3.38; 95% CI, 1.67–6.84), ICU admission (OR, 2.93; 95% CI, 1.28–6.69) and use of invasive mechanical ventilation (OR, 8.67, 95% CI, 3.88–19.39) were independently associated with greater odds of in-hospital death. Conclusion Several clinical characteristics were identified to be predictive of severe disease and in-hospital death among patients with underlying diabetes hospitalized with COVID-19.