Impact of leadership styles on teacher performance and student achievement in Philippine secondary schools

School leadership shapes not only organizational performance but also the daily experiences of teachers and the learning opportunities available to students, particularly in education systems operating under resource constraints. In Philippine secondary schools, where school leaders are expected to drive improvement amid complex classroom realities and limited institutional support, understanding which leadership approaches genuinely empower teachers and enhance student learning is a pressing concern. This study examined the effects of transformational, transactional, and laissez-faire leadership styles on teacher performance and student achievement in secondary schools in Lanao del Norte, Philippines. Survey data were collected from 28 school heads, 84 teachers, and 110 students and analyzed using correlation, regression, and analysis of variance techniques. Results indicate that transformational leadership is a strong and consistent predictor of teacher performance and student achievement, while transactional leadership shows weaker and less consistent effects and laissez-faire leadership is negatively associated with both outcomes. Significant differences in teacher performance were observed between public and private schools, underscoring the role of leadership context and organizational support. These findings highlight the practical importance of leadership practices that foster motivation, instructional support, and professional commitment, particularly in resource-constrained settings. By situating leadership effectiveness within the lived realities of Philippine schools, the study contributes context-sensitive evidence to leadership theory and supports policy and professional development initiatives aligned with Sustainable Development Goal 4: Quality Education.