Despite considerable evidence that police legitimacy results in beneficial outcomes like compliance, cooperation, and empowerment, scholars have yet to agree on how to define and operationalize legitimacy. Drawing on Max Weber’s facets of legitimacy, we developed and tested a measure of “traditional authority,” reflecting the possibility that some people legitimate the police more so based on tradition than normative concerns regarding fairness. Confirmatory factor analysis of survey data from a national sample of 701 US adults revealed that our traditional authority items loaded separately from items commonly used to capture feelings of trust, obligation to obey, and moral alignment. Furthermore, although perceived legitimacy appears to flow from perceptions of procedural and distributive fairness regardless of how it is measured, traditional authority is more strongly associated with empowerment of the police. We discuss the theoretical and practical implications of these findings and urge researchers to replicate and extend our work.