Observing workplace bullying could shape bystanders’ undesirable perceptions of their work. This study addresses a gap in the scarce literature on witnessing workplace bullying within public administration by examining the moderating role of moral disengagement in the relationships between ethical leadership (EL), witnessing workplace bullying, and employee perceptions of meaningful work (MNW). Aligned with Bandura’s (1991) overarching social cognitive theory of morality, we posit that EL, a critical component of work environment, diminishes instances of workplace bullying witnessed by bystanders while concurrently enhancing the perceived MNW of public servants. However, considering moral disengagement as cognitively moral judgement, it could crucially influence the impact of EL on witnessing workplace bullying and the subsequent effect of witnessing workplace bullying on perceived MNW. Leveraging a two-wave study involving 246 public sector employees in the United States, our findings reveal a negative association between EL and witnessing workplace bullying, alongside a positive relationship between EL and MNW. Moreover, witnessing workplace bullying is negatively associated with MNW. Intriguingly, low moral disengagement amplifies the impact of high EL on witnessing workplace bullying while intensifying the detrimental influence of witnessing workplace bullying on MNW. These results align with the social cognitive theory of morality perspective. We discuss theoretical contributions and offer managerial insights, particularly relevant for the public sector and broader organizational contexts.