PurposeThe coronavirus disease 2019 (COVID-19) pandemic brought out the best in people, but it also brought out the worst in people. Authorities grappled with the proliferation of misinformation, belief in conspiracy theories, distrust of authorities and anti-social behaviour. As frontline enforcers of COVID-19 restrictions, police were confronted with these attitudes and behaviours every day. This study examines whether the perceived trustworthiness of police during the pandemic – particularly procedural justice – protected public trust in police and reduced conspiracy theory uptake.Design/methodology/approachThis paper uses survey data collected from 779 Australians during the COVID-19 pandemic.FindingsFindings revealed that individuals who perceived police as untrustworthy during the pandemic, as well as those scoring high on conspiracy propensity, were less likely to trust police and were more likely to endorse COVID-19-specific conspiracy theories. Further, trust mediated the relationship between procedural justice and endorsement of conspiracy theories, and conspiracy propensity moderated the relationship between procedural justice and endorsement of conspiracy theories. Specifically, procedural justice protected trust most strongly for those low on conspiracy propensity, but reduced endorsement of COVID-19 conspiracy theories most strongly for those high on conspiracy propensity. Together, the findings show that procedural justice policing is critical for protecting trust in police and for mitigating conspiracy theory uptake.Originality/valueThe study makes a novel contribution to the policing, trust and conspiracy theory literature as it is the first to test whether conspiracy propensity moderates the relationship between procedural justice on peoples’ trust in police and their endorsement of conspiracy theories.