This chapter examines the functions of property rights in environmental law and governance. It reviews the role and nature of traditional property rights in political, economic and legal terms, and discusses the common law and legislative constraints on the exercise of those rights. The abstract and dynamic nature of property rights has allowed their adaptation and evolution to accommodate environmental challenges. New forms of property rights and trading systems have also been developed to achieve environmental objectives for natural resources such as water, fisheries and even clean air. Looking forward, the chapter argues that the normative principle of sustainability should be recognised as an inherent and universal obligation of private property ownership, and explicitly incorporated into law, policy and judicial decision-making to mitigate the ecological impact of the exercise of property rights.