Abstarct: The present study aimed to examine the effect of organizational climate on organizational citizenship behavior with the mediating role of psychological well-being among employees of the Departments of Sports and Youth in Salah al-Din. The research was descxriptive-correlational in nature and cross-sectional in terms of time. The statistical population included all employees of the Departments of Sports in Salah al-Din Province, and 163 participants were selected using convenience sampling. Data were collected using three standardized questionnaires: the 15-item Organizational Climate Questionnaire (2006), the 9-item Organizational Citizenship Behavior Questionnaire by Kanungo (1982), and the 5-item Psychological Well-being Questionnaire by Ryff and Singer (2002). To ensure content and face validity, the opinions of ten experts and professors in sports management were consulted, and the reliability of the instruments was confirmed using Cronbach's alpha. Structural equation modeling with a variance-baxsed approach was employed to test the hypotheses, and data analysis was conducted using SPSS 23 and Smart-PLS 4. The results indicated that organizational climate has a significant positive effect on both organizational citizenship behavior and psychological well-being. Psychological well-being also had a direct and significant effect on organizational citizenship behavior. Moreover, the mediating role of psychological well-being in the relationship between organizational climate and organizational citizenship behavior was confirmed. The findings suggest that a positive organizational climate, by providing a supportive and interactive environment, plays a key role in enhancing employees’ organizational citizenship behavior. Psychological well-being, as a mediating factor, strengthens the effect of organizational climate on employee participation, highlighting that simultaneous attention to improving organizational climate and enhancing employees’ psychological well-being can increase active participation, motivation, and organizational commitment. These results emphasize that managers of sports organizations should design appropriate managerial and psychological interventions, including strengthening social support, increasing opportunities for participatory decision-making, and reducing stressors, to foster psychological well-being and, consequently, improve organizational citizenship behavior.