Objectives The purpose of this study was to develop age‐ and sex‐specific waist circumference (WC) cut‐off points, linked to older adolescent and adult criteria for abdominal obesity, to be applied to children in the clinical setting. Methods A total of 16,788 adolescents aged 10 to 16 years were assessed for WC. Smoothed age and sex‐specific WC curves were obtained using Cole's LMS method. Results Percentiles that corresponded to the International Diabetes Federation (IDF) recommendations used for older adolescents and adults (16+ years old) were the 97th percentile for boys and the 87th percentile for girls. Using these cutoffs, a total of 368 boys and 1138 girls were categorized as abdominally obese, in contrast to 1654 boys and 987 girls that were identified using the current IDF pediatric criteria (90th percentile). Conclusions We provide age‐ and sex‐specific cut‐off points that can be used to identify abdominal obesity in adolescents. The present findings provide a tool that can be used in the clinical setting for the early detection and prevention of adult obesity. Population‐specific cutoffs may be required for pediatric ages to diagnose children at risk.