Purpose <p>The purpose of this study is to determine the effect of mental workload on psychological well-being among physical education and sports teachers and to examine the mediating role of perceived occupational stress and the moderating role of physical activity in this relationship.</p> Method <p>A correlational survey model was used in the study. Data were collected via a questionnaire from 450 physical education and sports teachers working in different regions of Turkey. Participants’ mental workload perceived occupational stress, psychological well-being, and physical activity levels were measured using scales with proven validity and reliability. Correlation analyses were performed using the SPSS program, while conditional indirect effect analyses were conducted within the framework of Hayes’ PROCESS Model 59.</p> Findings <p>The analysis results showed that mental workload significantly increased perceived occupational stress and that increased stress negatively affected psychological well-being. Furthermore, increased physical activity weakened the negative relationship between mental workload and psychological well-being. These results reveal that physical activity functions as a buffering resource in stress processes and supports teachers’ psychological resilience.</p> Conclusion <p>The research explains the interaction between teachers’ mental workload, stress, and well-being levels within a theoretical framework. The findings show that physical activity is not only a physiological but also a psychological protective factor. It is recommended that comprehensive policies be developed in educational institutions that reduce teachers’ mental workload, strengthen their stress management skills, and encourage physical activity-based practices.</p>