Purpose: We assessed the clinical relevance of waist-height ratio (WHtR) as an indicator of cardiometabolic risk and body fat mass measured by dual-energy x-ray absorptiometry (DXA) among Korean children and adolescents.Methods: Data from 1,661 children and adolescents aged 10–18 years who participated in the Korea National Health and Nutrition Examination Survey were analyzed. Unadjusted Pearson correlation, age- and sex-adjusted Pearson correlation, and multiple linear regression analyses were performed to investigate the relationships between WHtR standard deviation score (SDS) and cardiometabolic risk factors, as well as DXA-assessed parameters.Results: WHtR SDS was correlated with cardiometabolic risk factors, including systolic blood pressure, glucose, total cholesterol, high-density lipoprotein cholesterol, triglyceride, and low-density lipoprotein cholesterol, as well as DXA-assessed parameters such as lean mass SDS, fat mass SDS, and fat mass percentage SDS in both whole body and trunk using an adjusted Pearson correlation analyses among all participants (<i>p</i><0.001). WHtR SDS was strongly correlated with whole-body fat mass and trunk fat mass (r=0.792, <i>p</i><0.001 and r=0.801, <i>p</i><0.001, respectively) whereas WHtR SDS had a low correlation coefficient with whole-body lean mass and trunk lean mass SDS (r=0.512, <i>p</i><0.001 and r=0.487, <i>p</i><0.001, respectively). In multiple linear regression analyses, WHtR SDS was significantly associated with whole-body and trunk fat mass after adjustment for confounders.Conclusion: Cardiometabolic risk factors and body fat mass assessed by DXA in Korean children and adolescents were highly correlated with WHtR. Additionally, WHtR has an advantage in distinguishing fat-free mass. WHtR can be a useful and convenient clinical indicator of cardiometabolic risk factors.