Dyslipidemia in adolescents represents an early and potentially modifiable stage in the lifelong trajectory of cardiovascular disease. However, optimal lipid screening strategies in this age group remain controversial, particularly regarding feasibility, biological relevance, and reliance on family history. Non-high-density lipoprotein cholesterol (non-HDL cholesterol) has emerged as a promising screening marker because it reflects the total burden of atherogenic lipoproteins and can be reliably assessed even without fasting, making it particularly suitable for large-scale pediatric screening settings. A recent nationwide population-based study of Korean adolescents provides robust real-world evidence supporting the utility of non-HDL cholesterol in dyslipidemia screening, across both sexes and independent of familial lipid risk. From a nutritional and public health perspective, non-HDL cholesterol is closely related to dietary habits, postprandial hyperlipidemia, and metabolic stress, and is particularly important in the modern food environment characterized by increased consumption of ultra-processed foods. This Opinion discusses the biological rationale, clinical feasibility, and population-level implications of non-HDL cholesterol-based screening in adolescents. By linking lipid biology with nutrition-focused prevention and lifelong cardiovascular health, non-HDL cholesterol may serve as a practical gatekeeper for early risk identification and upstream intervention.