ABSTRACT The present study examined the possibility of Belief in a Just World (BJW) acting as a personal resource for police officers, simultaneously protecting their well-being through voice behaviour, vertical trust, and work-family conflict. The sample comprised 573 police officers who voluntarily consented to answer an anonymous online survey. Self-reported measures of personal BJW, voice behaviour, vertical trust, work-family conflict, and well-being were collected. The results of a parallel multiple mediator model (controlling for quantitative demands) showed that all three mediators were significant. Therefore, we found support for BJW acting as a personal resource by simultaneously protecting police officers’ well-being through boosting both voice behaviour and vertical trust, and reducing work-family conflict. Work-family conflict was found to have the largest effect size in the mediation mechanism between BJW and police officers’ well-being. The implications of these results for future research and intervention in police organisations are discussed.