Ecological restoration has only become legal as an international environmental law (IEL) obligation within the last half-century. However, the practice of ecological restoration is not an entirely new phenomenon historically. The evolution of the international legal framework for ecological restoration only began with the adoption of the first multilateral environmental agreements (MEAs) in the early 1970s. Since then, however, states have entered into several MEAs in pursuit of ecological restoration, which broadly fall into two categories: species recovery and habitat restoration treaties. The UN General Assembly recently declared 2021–2030 the UN Decade on Ecosystem Restoration to reverse ecosystem degradation, fight the climate crisis and reverse biodiversity loss. Implementing plans to promote effective law and policy within ecological restoration would require a binding Protocol on Ecological Restoration to the Convention on Biological Diversity (CBD) that commits states to develop restoration strategies in collaboration with other social sectors. This chapter maps the emerging legal framework for ecological restoration in IEL. It begins with the international soft law context for environmental restoration under the 1972 Stockholm Declaration. In taking stock of the legal developments under selected species recovery and habitat restoration treaties, the chapter analyses the potential role of the UN Decade on Ecosystem Restoration in shaping the future of ecological restoration in IEL. The chapter argues that a protocol for ecological restoration could potentially build on past recommendations of the CBD Subsidiary Body for states to engage in short-term ecosystem restoration planning. The chapter thus addresses why countries with ecological governance challenges should be concerned with applying restoration obligations in their domestic environmental law and policy.