Greater consumption of red meat has been linked to a higher risk of mortality and chronic diseases, including diabetes. We aim to examine the associations between total, processed, and unprocessed red meat intake and diabetes, and to evaluate the substitution effects of other protein sources for red meat on diabetes. This population-based cross-sectional study utilized data from the National Health and Nutrition Examination Survey (NHANES) 2003-2016. Diabetes was defined as being diagnosed by a physician or other health professional, having a fasting plasma glucose of 126 mg/dL or higher, an HbA1c level of 6.5% or higher, or the use of antidiabetic drugs. Multivariable logistic regression models were conducted. The study included 34,737 adult participants (mean (SD) age of 45.8 (17.5) years) from NHANES 2003-2016. After adjusting for major confounders, compared to the first quintile, higher intakes of total, processed, and unprocessed red meat were positively associated with higher odds of diabetes, with adjusted odds ratios of 1.49 (95% CI, 1.22-1.81), 1.47 (95% CI, 1.17-1.84), and 1.24 (95% CI, 1.06-1.44), respectively (P- trend for all < 0. 001). In this nationally representative sample of U.S. adults, participants in the highest quintiles of total, processed, and unprocessed red meat intake had higher odds of diabetes than those in the lowest quintile. Substituting 1 serving/day of dietary protein from foods of plant origin (including nuts, seeds, legumes, and soy) for total, processed, or unprocessed red meat was associated with 9% to 14% lower odds of diabetes.