Objective: This research aims to assess job satisfaction's mediating role between transformational leadership (TL), work environment (WE), knowledge management (KM) practices, and employee performance (EP) by investigating TL's and WE's impact on job satisfaction, and examining how job satisfaction mediates the relationships between TL, KM practices, and EP. Theoretical Framework: The theoretical framework examines key factors affecting employee performance and organizational success. It highlights task and contextual performance, environmental influences, and the role of performance appraisals. Effective human resource practices, knowledge management, and transformational leadership are essential for high performance. Job satisfaction, influenced by knowledge management and leadership, enhances organizational success. Method: This quantitative study investigates the relationships among transformational leadership (TL), work environment (WE), job satisfaction (JS), knowledge management (KM) practices, and employee performance (EP). Data from 411 Thai-speaking participants are analyzed using structural equation modeling (SEM). The study employs validated questionnaires, a 5-point Likert scale, and ADANCO software to assess model fit, reliability, and validity. Results: The sample predominantly comprised females (64.7%) and individuals with bachelor’s degrees (59.12%), with 31.87% employed in companies and 41.12% earning between 30,001 and 50,000 baht. Descriptive analysis revealed strong positive perceptions of KM, TL, WE, JS, and EP, with mean scores between 4.74 and 4.87, underscoring the focus on EP. Structural equation modeling (SEM) identified significant relationships between KM and JS (0.0277), TL and JS (0.0533), WE and JS (0.1720), and JS and EP (0.4721). JS emerged as a key mediator between KM, TL, and WE, accounting for substantial variance in both JS and EP, reflected by R² values of 0.0385 and 0.3283. Although the KM-JS and TL-JS relationships were relatively weak, JS significantly influenced EP. The study advocates for enhancing KM, TL, and WE to improve JS and EP, while recommending future research to investigate moderating factors, longitudinal designs, and cross-cultural contexts. Research Implications: The study reveals critical insights into job satisfaction (JS) as a mediator between transformational leadership (TL), knowledge management (KM), work environment (WE), and employee performance (EP): TL significantly influences KM and WE, while effective KM enhances EP. JS mediates the positive effects of TL, KM, and WE on EP, though moderate correlations suggest other influencing factors. The research emphasizes contextual nuances within Thai organizations, underscoring the complexity of these relationships and the need for further investigation to fully understand their organizational implications. Originality/Value: This study offers innovative insights into the interactions among Knowledge Management (KM), Transformational Leadership (TL), Work Environment (WE), Job Satisfaction (JS), and Employee Performance (EP) in Thai organizations. It identifies JS as a key mediator in the effects of KM, TL, and WE on EP, deepening the understanding of organizational dynamics. Moderate correlations between KM and JS, and TL and JS, suggest additional moderating factors. The pivotal role of JS in determining EP emphasizes the need for organizations to enhance JS to improve performance. The study's focus on Thai organizations highlights cultural and contextual influences, bridging local practices with broader theoretical frameworks. Further investigation is needed to fully understand these complex dynamics.