Early screening prevents chronic diseases by identifying at-risk adolescents through anthropometric measurements, but predictive value in diverse groups is uncertain. A cross-sectional analysis of 12- to 19-year-old individuals from the 2017-2018 National Health and Nutrition Examination Survey (NHANES) assessed the predictive ability of BMI percentile, total body fat percentage, waist circumference (WC), and waist-hip ratio (WHR) for four cardiometabolic risk factors across race and ethnicity groups using receiver operating characteristic curves. The unweighted sample (N = 1194; 51.2% male individuals; 23.7% Hispanic, 13.2% non-Hispanic Black [NHB], 51.1% non-Hispanic White [NHW], 12.0% other/multirace) had a weighted prevalence of elevated blood pressure of 2.7%, hyperglycemia of 36.8%, hypertriglyceridemia of 4.8%, and low high-density lipoprotein (HDL) cholesterol of 15%. WHR (area under the curve [AUC] = 0.77), WC (AUC = 0.77), and BMI percentile (AUC = 0.73) outperformed total body fat percentage (AUC = 0.56) in predicting elevated blood pressure (p < 0.001 for all). BMI percentile was more accurate than total body fat percentage in predicting hypertriglyceridemia (AUC = 0.70 vs. 0.59; p = 0.02) and low HDL cholesterol (AUC = 0.69 vs. 0.59; p < 0.001). Race and ethnicity-based predictions varied: NHW adolescents had the highest AUC (0.89; p < 0.01) for elevated blood pressure prediction compared with Hispanic and NHB adolescents (AUC = 0.77 for both). Total body fat percentage was more accurate in predicting low HDL cholesterol among Hispanic versus NHW adolescents (AUC = 0.73 vs. 0.58; p = 0.04). WHR, WC, and BMI percentile are better predictors of cardiometabolic risk factors in adolescents than total body fat percentage. Predictive abilities differed by race and ethnicity, highlighting the importance of tailored risk assessment strategies.