Educational change research has long emphasized the roles of key leaders, organizational capacity, and culture in improvement efforts, yet conventional quantitative approaches often treat individuals as independent and overlook the relational infrastructures through which change actually occurs. This chapter argues that social network analysis (SNA), aligned with complex systems theory, offers a systems-focused methodological and conceptual toolkit for examining educational change in leadership and policy. We review foundational SNA concepts (e.g., nodes, ties, dyads) and key individual- and whole-network measures (e.g., degree, betweenness, closeness, density, reciprocity), alongside methodological considerations. We show how SNA makes visible relational conditions that facilitate change—particularly trust, brokerage across silos, and the diffusion and use of research evidence—while also illuminating relational barriers such as leadership churn, fragmentation, and inequitable access to influential networks. We also demonstrate how policy advocacy, influence, and implementation can be analyzed as networked processes shaped by coalitions and power. Finally, we highlight emerging directions, including critical network analysis (CNA) that center power and structural inequity, and call for more longitudinal, mixed-method, and participatory designs capable of capturing nonlinear dynamics and emergent system shifts.