Work-related stress and workplace deviant behavior are major concerns in modern organizations, particularly in academic and administrative settings. This study investigates the mediating roles of work-family conflict (WFC) and family-work conflict (FWC) in the relationship between job stress and workplace deviance. While prior research has established a link between stress and deviant behavior, few studies have explored how conflicts between professional and personal responsibilities influence this connection. To bridge this gap, an online survey was conducted with a randomly selected sample of 193 academic and administrative employees from an Egyptian university. A quantitative research approach was adopted, incorporating exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) to validate measurement models. Regression analysis was employed to examine direct relationships, while mediation analysis assessed the indirect effects of WFC and FWC on the stress-deviance relationship. The results indicate that work-related stress significantly predicts both WFC and FWC. However, only FWC mediates the link between stress and workplace deviance, whereas WFC does not play a mediating role. These findings highlight the need to address family-related conflicts to mitigate workplace deviance. Organizations can reduce such behaviors by implementing policies that promote work-life balance and provide greater support for employees.