The incidence of diabetes and obesity has reached epidemic levels. Although insulin resistance is the key pathophysiological mechanism, several surrogate biomarkers of insulin resistance such as Homeostatic Model Assessment for Insulin Resistance (HOMA-IR), have been proposed. In recent years, research on triglyceride-glucose (TyG) index as a useful marker for identifying cardio-metabolic risk, particularly in adults, has been on the rise. However, there is a paucity of data on the role of the TyG index in children and adolescents and the association of the TyG index with HOMA-IR and DEXA (dual-energy X-ray absorptiometry), especially in North America. Therefore, this study aims to investigate the role of the TyG index in children and adolescents, and explore the relationship between the TyG index and HOMA-IR and DEXA in North American children and adolescents. Forty-four lean and obese children and adolescents were recruited after obtaining informed consent, anthropometric and laboratory assessments. TyG index was significantly higher in obese children and adolescents than in their lean counterparts (p < 0.001) and correlated significantly with glucose, BMI, DEXA, triglycerides and HOMA-IR. Thus, this pilot study shows that the TyG index may serve as an excellent surrogate for assessing cardio-metabolic risk in pediatrics.