Leadership transitions frequently serve as critical turning points in the direction, speed, and sustainability of organizational reform. This study examines how leadership change shapes reform trajectories across administrative institutions by analyzing the relationship between transition patterns, leadership style, institutional capacity, and reform outcomes. Drawing on a multi-institutional dataset constructed to reflect realistic public sector conditions, the study applies a comparative analytical framework to evaluate variations in reform continuity, implementation speed, employee alignment, and perceived administrative effectiveness. The findings indicate that leadership changes characterized by strategic continuity, participatory communication, and procedural legitimacy are more likely to generate stable and progressive reform trajectories, whereas abrupt or politically contested transitions tend to produce implementation delays, staff resistance, and fragmented policy execution. The study further suggests that institutional preparedness and middle-management support mediate the effects of leadership turnover on reform performance. By integrating leadership theory with reform process analysis, the paper contributes to the public administration literature by offering a structured explanation of why some leadership transitions accelerate reform while others disrupt it. The study concludes with implications for succession planning, administrative resilience, and future research on leadership-driven institutional transformation