Supply chain resilience (SCR) has long been recognized as crucial to survival in today’s turbulent environment. Despite extensive discussions on supplier concentration, the insights into its role in achieving SCR remain limited and inconsistent. To provide a more balanced view, the complex influence of supplier concentration on SCR is examined through the perspective of resource dependence theory (RDT). This research hypothesizes an inverted U-shaped relationship between supplier concentration and SCR, with digitalization and information transparency acting as moderating factors. This relationship is supported by our empirical evidence based on a sample of 2278 Chinese listed firms during 2008–2022. Interestingly, our findings indicate that the inverted U-shaped relationship is flattened by digitalization, but steepened by information transparency of the focal firm. Both moderators shift the turning point of the curve to the right. Notably, the curvilinear relationship is stronger in firms with high market share, non-state-owned enterprises, firms operating in highly competitive industries, and those located in regions with strong institutional development. Additionally, our further analysis shows that digitalization and information transparency independently influence how supplier concentration affects SCR, but their effects do not reinforce each other when considered jointly. The curvilinear relationship operates through the supply chain governance efficiency mechanism and the opportunism–uncertainty mechanism. This work contributes to the understanding of SCR determinants and the literature on optimal supplier concentration. It also provides practical implications for business practitioners and policymakers, offering valuable insights into how to manage supplier concentration to enhance overall resilience.