Abstract. This study explored how school principals’ social competence influences performance in public basic education institutions in Glan, Sarangani Province. As leadership is a cornerstone of school effectiveness, the research focused on six dimensions of social competence: self-management, interpersonal skills, positive self-identity, cultural skills, planning and decision-making, and adapting to social values. Eight principals and 166 teachers participated. Principals' social competence was assessed through validated surveys, while school performance was measured using results from the Early Language, Literacy, and Numeracy Assessment (ELLNA) and the National Achievement Test (NAT). Findings showed both principals and teachers consistently rated social competence as outstanding, with the highest scores in "adapting to social values." However, performance indicators, especially NAT results for Grade 12, remained in the “Needs Improvement” range. No significant difference was found between principals’ self-ratings and teachers’ assessments. Regression analysis also revealed no significant relationship between social competence and school performance. The results suggest high social competence does not directly translate to improved academic outcomes. The study recommends strengthening social-emotional leadership skills while addressing systemic student achievement challenges. Future research should include additional factors such as instructional supervision and school resources for a more comprehensive view of school performance.

Keywords: ELLNA; NAT; Principal effectiveness; School performance; social competence.