This study examined the predictive validity of musculoskeletal fitness tests for identifying sarcopenia in youth. The sample was 529 participants age 10 to 18 years. Indices included: total lean body mass (LBM) normalized for height (LBM index, LBMI, kg/m2), appendicular LBMI (aLBMI, kg/m[superscript 2]), and LBM to fat body mass (FBM) ratio (LBM/FBM). Lean and fat tissue were measured via DXA. The cutoff value for sarcopenia was -- 2.0 standard deviations [less than or equal to] mean for age and sex. Fitness was assessed using handgrip, plank, and vertical jump tests. Variables were standardized using the lambda-mu-sigma (LMS) method. By sex, analysis included the area under the curve (AUC), sensitivity (Se), and specificity (Sp). The ROC curves for aLBMI was highly accurate (AUCs [greater than or equal to] 0.90, Se and Sp = 86-88%) for vertical jump and moderately accurate for handgrip (AUCs = 0.87-0.88, Se and Sp = 71-75%). Fitness tests can be used to identify pediatric sarcopenia.