The purpose of this study was to examine the influence of Supreme Elementary Learner Government (SELG) participation on the leadership development and civic engagement of elementary learners. A predictive research design was utilized to determine the relationships and predictive effects among the study variables. The respondents consisted of 70 SELG officers selected through universal sampling. Data were gathered using an adapted survey questionnaire and analyzed using mean and standard deviation, Pearson product–moment correlation, and multiple linear regression analysis to identify significant relationships and predictors. Findings revealed that SELG participation was generally moderate to high, while leadership development and civic engagement varied across indicators, with leadership skills and community involvement at a high level, and civic responsibility and awareness, as well as social influence and peer interaction, at a moderate level. Results further showed a significant but low positive relationship between SELG participation and leadership development and civic engagement. Among the indicators of SELG participation, only role engagement emerged as a significant predictor, while level of involvement and frequency of engagement did not show a significant predictive influence. The findings underscore the importance of assigning meaningful and well-defined roles in strengthening leadership competencies and civic responsibility among elementary learners.