This study investigated the relationship between junior high school students’ self-concept in Chemistry and their academic performance in the subject. A quantitative descriptive correlational design was used. Participants were 300 students from Davao City National High School who had complete data on a standardized Chemistry self-concept questionnaire by Emmanuel Uwadone and official Chemistry grades. Self-concept scores were obtained from a validated Likert type instrument, and grades were taken from school records for a completed grading period. Descriptive statistics, assumption checks, correlational analyses, and simple linear regression were conducted. Results showed that Chemistry grades were generally high and moderately dispersed, whereas self-concept scores were more variable and positively skewed. Pearson product moment correlation indicated a significant moderate positive relationship between self-concept and Chemistry grades, r = 0.400, p < .001. Spearman rank correlation produced a comparable coefficient, ρ = 0.417, p < .001, which confirmed that the association was robust to non-normality and potential outliers. Regression analysis further showed that self-concept significantly predicted Chemistry grades and accounted for approximately 16 percent of the variance in academic performance. The findings suggested that students who held more positive beliefs about their capability in Chemistry tended to obtain higher grades, although self-concept represented only one of several influences on achievement. The pattern of high grades but uneven self-concept highlighted the need to address possible underestimation of competence among some students. The study underscored the importance of classroom practices that support both academic performance and adaptive self-beliefs in Chemistry at the junior high level.