This study addresses an existing research gap on individual green competences (GC) and their application in business settings, and discusses the concept GC in the context of a firm's organizational sustainability (OS). Namely, the study aims to examine the importance of organization members' (managers' and employees') GC for advancing a firm's OS. The theoretical grounding is exemplified by the empirical study based on individual interviews with managers. Study results explain how managers understand GC and how they see GC's role in enhancing companies' OS, as well as what are crucial barriers encountered in this process. The results show that GC, from a managerial perspective, are seen through the lens of people's pro‐environmental awareness and knowledge followed by behaviors related to environmental protection. They indicate the economic, environmental, and social benefits of GC development, required for a firm's competitive advantage. The research contributes to the studies on GC being a significant antecedent of achieving the desired business results in terms of OS.