Research suggests perceptions of neighborhood social dynamics and judgments that the police follow fair procedures are strongly correlated with residents’ views of police legitimacy. The nature of these relationships is less clear, including the extent to which the association between informal neighborhood dynamics and police legitimacy is influenced by perceptions of police practice. We examined whether perceptions of procedural justice moderate the effect of collective efficacy beliefs on police legitimacy evaluations. Utilizing data from three city-level victimization surveys (N = 2,837), we found that the influence of collective efficacy beliefs on police legitimacy evaluations was moderated by judgments that the police follow fair procedures. When perceptions of procedural justice are at their mean or higher, collective efficacy beliefs are unassociated with police legitimacy. Conversely, collective efficacy beliefs have a stronger impact on legitimacy evaluations when procedural justice is low. Results suggest perceptions that police treat people fairly minimize the impact of low collective efficacy beliefs on police legitimacy evaluations.