This study examines how Digital Transformation (DT) influences Firm Performance (FP) and investigates the moderating role of Leadership Agility (LA) in Vietnamese small and medium-sized enterprises (SMEs). Drawing on Dynamic Capabilities Theory and Contingency Theory, the research proposes that DT enhances FP through process reconfiguration, improved information flows, and innovation capability, while LA strengthens this relationship by enabling leaders to respond rapidly to environmental uncertainty and align digital initiatives with organizational needs. A quantitative design was applied using survey data collected from 270 middle- and senior-level managers across various industries. Structural Equation Modeling (SEM) was used to test the hypothesized relationships. The results reveal that DT exerts a significant positive effect on FP, LA directly improves FP, and LA significantly moderates the DT–FP relationship, with stronger effects observed under high levels of leadership agility. The findings contribute to the literature by integrating LA into the DT -performance framework in an emerging economy context. Practical implications highlight the importance of developing agile leadership capabilities to ensure the successful implementation of digital initiatives and enhance organizational performance.