This article reviews the evidence on public knowledge of crime and criminal justice across a number of countries and discusses the implications of public knowledge for public opinion of crime and criminal justice, as well as policymaking. It introduces and explores the concept of public narratives on crime and criminal justice to provide a context for public knowledge and discusses the importance of the stories people tell about crime and criminal justice. The article sets out what the public knows about crime and criminal justice, why this matters (i.e., how knowledge is thought to influence public opinion on crime and criminal justice), approaches to addressing a lack of public knowledge, and the contribution of public narratives to this debate. It suggests that the importance of public knowledge of crime and criminal justice has been overstated.