This essay considers the nature and importance of legitimacy in the context of policing policy and practice. On what basis is police legitimacy established, maintained and undermined? What are the implications of the extant body of empirical evidence for policing policy and practice? We concentrate on Tyler’s procedural justice model. But we also consider the idea that police legitimacy is partly based on the strength of informal social control processes operating at the neighborhood level: citizens grant the police power in exchange for social order; they cede power and authority to the police in exchange for social regulation and justice; and this conferral of power and consent to police authority may, to some degree, depend upon the strength of social order at a local level.