The present study sought to examine self-control, parental support, and peer support as internal and external protective factors that buffer the influence of adolescent stress on delinquency among Korean adolescents. To this end, the paper utilized the 1st-year data from the Korea Youth Panel Study (KYPS) conducted by the National Youth Policy Institute; the study surveyed a total of 3,449 2nd-year middle school students. The results of the hierarchical regression analysis indicated that despite high levels of stress, high self-control mitigated the negative influence of stress on delinquency in adolescents. In contrast, parental and peer support were only found to be directly influential on juvenile delinquency. Parental support had only negative influences on status delinquency, and peer support had positive influences on both status and serious delinquency. Based on these results, we propose implications for preventing and intervening with juvenile delinquency.