The main objective of this research was to systematically review the effect of social identity and social contexts on the association between procedural justice and legitimacy in policing. To achieve this a meta-analysis method has been employed, synthesizing data from 123 studies (N = 200,966) addressing the relationship between procedural justice and legitimacy in policing. Random-effects univariate and two-stage structural equation modelling meta-analyses were performed. The study concluded that both procedural justice and social identity are found to be significantly correlated with police legitimacy. Moreover, social identity significantly mediates, but does not moderate, the association between procedural justice and legitimacy. People of younger age and from more developed countries tend to correlate procedural justice stronger with police legitimacy. This study demonstrates that social identity is an important antecedent of legitimacy and a critical factor in the dynamics of procedural fairness in policing. It also shows that the extent to which procedural justice and legitimacy are correlated varies across social groups and contexts. The theoretical implications of our findings are discussed.