Purpose: While leadership in educational contexts has been widely studied, less is known about how leadership dynamics shape social influence networks within school ecosystems. This study addresses this gap by examining how leadership structures social networks during educational reform, drawing on social network theory and a distributed leadership perspective. Design/methodology/approach: Using a multi-case network design, this study analyzes longitudinal social network data alongside qualitative data from staff in two comparable elementary schools with distinct leadership approaches to reform. Conceptualizing leadership as a social influence phenomenon, the study explores how leadership dynamics interact with school networks to shape collaboration and professional relationships within school ecosystems. Findings: Results indicate differences in the principals' network positions and the influence of their leadership teams, with tie formations reflecting each school's leadership approach and social infrastructure. Specifically, the extent to which leadership is prescriptive or discretionary influences principals' positions within their schools' social networks, shaping how expertise is distributed and how collaboration unfolds across professional communities. Originality/value: This study contributes to the literature by demonstrating how leadership approaches shape social influence networks within school ecosystems. By examining leadership strategies in the context of reform, it illustrates their role in structuring professional networks that facilitate collaboration and sustain reform efforts. The findings offer insights for practitioners and policymakers on leveraging leadership practices to strengthen professional communities and build collective capacity within schools' learning ecosystems.