In most ancient cultures, what we now call religion was interwoven throughout all aspects of life and did not always form a discrete cultural domain. Nevertheless, its principal symbols and traditions can be sufficiently distinguished to allow for a fruitful examination of the relationship of law and religion in antiquity. This chapter pursues that endeavour, with particular attention to instances when the sources at our disposal indicate, explicitly or implicitly, that law was relying on religious ideas to achieve legal ends. The chapter considers the role of religion in legitimizing law, in public law and governance, in legal transactions and proceedings, and in the determination and punishment of wrongdoing. It ultimately seeks to add clarity and specificity to the scholarly description of how law and religion interacted in the ancient world.