This chapter examines the role of evidence in public service reform processes. We argue that the rhetoric of ‘evidence-based policy-making’ has served several political agendas, by legitimising various logics of public service management and innovation, and marginalising others. We explore three management cultures (public administration, new public management, and public value management) and three themes—evidence generation, evidence use, and organisational learning—across the policy domains of higher education, healthcare policy, and broader science policy. We conclude that we urgently need more empirical evidence about who gets to participate in knowledge production, the roles of power and different forms of knowledge, how credibility and legitimacy are framed and negotiated in different public and policy contexts, and how to best investigate these processes to deliver meaningful public value.