This chapter provides an overview of the current state of the literature on public opinion and legitimacy of the courts. It begins by outlining the competing theoretical perspectives and giving an overview of the state of the empirical literature for different courts and countries. It then proceeds to examine the main data and methodological issues that have occupied the literature, outlines the main findings, and provides a discussion of the challenges facing the literature. A major theme that emerges is that the competing theoretical perspectives have produced conflicting results, leaving the literature in a state of flux on key issues such as the stability of legitimacy over time, the importance of policy disagreement, and the relationship between diffuse and specific support. The chapter concludes by mapping a potential path forward with a plea for researchers on both sides of the theoretical divide to iron out their methodological differences, including agreeing on an appropriate measure of legitimacy that can inform future research.