Adolescence is a developmental period characterized by various physical, cognitive, emotional, and social changes that can increase vulnerability to psychological distress. One issue requiring attention is self-harm, which can be associated with difficulties in emotional regulation, family problems, social pressure, and negative self-evaluation. Self-esteem is hypothesized to be an internal protective factor. This study aimed to determine the influence of self-esteem on the risk of self-harm among high school adolescents. A quantitative approach was employed, utilizing correlation analysis and simple linear regression. The study involved 29 respondents, using instruments comprising 10 items measuring self-esteem and 10 items assessing self-harm risk. The results indicated that the majority of respondents (62.1%) fell into the high self-esteem category, while the highest proportion of respondents (44.8%) fell into the moderate category for self-harm risk. Pearson correlation analysis revealed a significant negative relationship between self-esteem and self-harm risk (r = -0.630; p < 0.001). Simple linear regression analysis also yielded a significant model (F(1,27) = 17.727; p < 0.001) with an R² value of 0.396. The regression coefficient of -1.355 indicates that an increase in self-esteem is associated with a decrease in self-harm risk scores. Thus, self-esteem can be viewed as a protective factor with the potential to support promotive and preventive efforts regarding self-harm risk among adolescents in school settings. However, these findings should be interpreted with caution due to the relatively small sample size and the multifactorial nature of self-harm.