This study investigated associations between healthy dietary practices and the odds of prediabetes among Korean adolescents. The data of 1,624 adolescents aged 12 to 18 who participated in the 2017-2021 Korea National Health and Nutrition Examination Survey were analyzed. Healthy dietary practices were defined according to Health Plan 2030 criteria, and prediabetes was defined as a fasting blood glucose level of 100-125 mg/dL. After controlling for confounders, adjusting odds ratios and 95% confidence intervals (CIs) for prediabetes were determined for different healthy dietary practices using multivariable logistic regression analysis. Compared with adolescents who engaged in healthy dietary practices, those who did not had a 1.63-fold (95% CI: 1.12-2.37) higher odds of prediabetes. In addition, adolescents who did not consume ≥500 g of fruit and vegetables daily and those who refrained from reading nutritional fact labels, which are both subindicators of healthy dietary practices, had a 1.66 (95% CI: 1.05-2.62) and 1.58-fold (95% CI: 1.06-2.37) higher odds of prediabetes, respectively, than those who did. Increasing the proportion of adolescents engaging in healthy dietary practices, such as consuming ≥500 g of fruit and vegetables daily and reading nutritional fact labels when selecting food, is imperative.