<p>Correctional employees work in environments characterized by high occupational demands, organizational constraints, and frequent exposure to psychological stressors. Previous correctional-staff research has highlighted the importance of organizational justice, work–family dynamics, organizational support, and burnout in shaping employee well-being. However, limited evidence has examined how these factors jointly relate to mental health within non-Western correctional systems. Drawing on Conservation of Resources (COR) Theory and Social Exchange Theory (SET), this study explores how perceived organizational support (POS) and work–life balance (WLB) are associated with mental health among correctional staff and examines the roles of organizational justice (OJ) and job burnout (JB) within an integrated exploratory framework. A cross-sectional survey was conducted among correctional staff employed in correctional institutions in Hamedan Province, Iran. Data were collected from 56 participants using established and validated measures of perceived organizational support, work–life balance, organizational justice, job burnout, and mental health. Reliability and validity were assessed using Cronbach’s alpha, exploratory factor analysis (EFA), and confirmatory factor analysis (CFA). Relationships among variables were examined through correlation analysis, multiple regression, bootstrapped mediation analysis, moderation analysis using Hayes’ PROCESS macro, and exploratory structural equation modeling (SEM). Perceived organizational support and work–life balance were positively associated with mental health. Organizational justice mediated the relationship between perceived organizational support and mental health, while job burnout partially mediated the association between work–life balance and mental health. Organizational justice also moderated the relationship between work–life balance and mental health, such that the positive association was stronger under conditions of higher perceived fairness. The exploratory structural model demonstrated acceptable fit and explained a substantial proportion of variance in mental health. Consistent with previous correctional-staff research, the findings highlight the importance of organizational resources, fairness perceptions, and burnout-related processes in understanding employee well-being. The study contributes to the correctional-staff literature by integrating perceived organizational support, work–life balance, organizational justice, burnout, and mental health within a single exploratory framework. Rather than proposing entirely new mechanisms, the findings extend existing correctional and occupational-health research by examining these relationships in an underrepresented non-Western correctional context. The study further illustrates how organizational justice may function simultaneously as a mediating and moderating mechanism within a resource-based perspective on employee mental health.</p>