The growing pressures from the government, buyers, consumers, suppliers, and the general public have recently compelled manufacturing firms to enhance their production methods by becoming more environmentally friendly and pursuing new innovative methods for producing green goods in developing countries. However, the relationship between green supply chain management (GSCM), green human capital (GHC), green innovation (GIN), managerial environmental knowledge (MEK), and firm performance (FPR) has received only a minimal amount of research focus. This study addresses this research gap by providing empirical evidence to motivate firms to implement GSCM, GHC, GIN, and MEK to enhance their FPR in developing countries substantially. A conceptual framework was developed to connect the concepts mentioned above. A questionnaire-based survey was used to collect the data. A total of 736 respondents from manufacturing firms in China were selected. Utilizing structural equation modeling (SEM), the data were analyzed. The findings indicate that neither GHC nor GSCM directly affects FPR; rather, GIN mediates the connection between GHC, GSCM, and FPR. In addition, the findings showed that MEK directly affects FPR and moderates the link between GIN and FPR. This study examined several theoretical and managerial implications and expanded research in the related fields. The results may help practitioners and managers comprehend how GSCM practices impact GIN and FPR. The outcomes of this research will benefit experts, policy makers, and stakeholders who seek to encourage FPR enhancements.