This article examines the critical role of employee mental well-being as a mediating factor in the relationship between job roles & responsibilities and productivity. Drawing from organizational psychology and human resource management literature, we explore how role clarity, supportive environments, and effective coping strategies influence productivity through psychological health. We review empirical evidence on job design, organizational support, and work-life dynamics and propose a conceptual framework to highlight how mental well-being bridges the gap between organizational expectations and employee performance. Recommendations for future research, theory, and practical implementation are subsequently discussed, emphasizing the importance of mental well-being in fostering sustainable productivity.