Humanitarian logistics firms face persistent challenges in achieving efficiency, sustainability, and stakeholder satisfaction due to the complexity of supply chain operations and resource constraints. Previous studies have examined supply chain resilience, procurement, and sustainability but have often overlooked the mediating role of leadership in linking humanitarian supply chain management (HSCM) factors to organizational performance, creating a need for further investigation. The aim of this study was to examine the mediating effect of leadership on the relationship between HSCM factors coordination, procurement, operations, and transparency and the performance of humanitarian logistics firms in Borno State, Nigeria. A quantitative research design was adopted, with data collected through structured questionnaires from a sample of 278 managers determined using Krejcie and Morgan’s table and validated by G*Power analysis. Partial Least Squares Structural Equation Modeling (PLS-SEM) was employed to test the hypothesized relationships. The results revealed that leadership measured through superior influence significantly mediated the effects of coordination and transparency on performance outcomes, including cost efficiency (O = 0.177, T = 3.170, p = 0.002), goal achievement (O = 0.200, T = 3.143, p = 0.002), operational efficiency (O = 0.197, T = 3.120, p = 0.002), and stakeholder satisfaction (O = 0.243, T = 3.113, p = 0.002). Transparency also showed strong mediation effects through superior influence on cost efficiency (O = 0.285, T = 3.965, p < 0.001), goal achievement (O = 0.320, T = 4.104, p < 0.001), operational efficiency (O = 0.315, T = 4.041, p < 0.001), and stakeholder satisfaction (O = 0.391, T = 4.112, p < 0.001). In contrast, leadership measured through strategic vision did not yield significant mediation effects across the tested relationships. The study concluded that superior influence is a critical leadership dimension in enhancing the impact of coordination and transparency on humanitarian logistics performance, while strategic vision alone is insufficient. These findings contribute to theory by positioning leadership as a mediating construct and provide practical implications for humanitarian organizations seeking to strengthen resilience, efficiency, and sustainability in complex operational environments.