Marking 150 years since Confederation provides an opportunity for Canadian international law practitioners and scholars to reflect on Canada’s rich history in international law and governance, where we find ourselves today in the community of nations, and how we might help shape a future in which Canada’s rules-based and progressive approach to international law gains ascendancy. This collection of essays, each written in the official language chosen by the authors, provides a thoughtful perspective on Canada’s past and present in international law, surveys the challenges that lie before us, and offers renewed focus for Canada’s pursuit of global justice and the rule of law. Part I explores the history and practice of international law, including sources of international law, Indigenous treaties, international treaty diplomacy, domestic reception of international law, and Parliament’s role in international law. Part II explores Canada’s role in international law, governance and innovation in the broad fields of economic, environmental, and intellectual property law. Part III explores Canadian perspectives on developments in international human rights and humanitarian law, including judicial implementation of these obligations, international labour law, business and human rights, international criminal law, war crimes, child soldiers, and gender. Reflections on Canada’s Past, Present and Future in International Law/Réflexions sur le passé, le présent et l’avenir du Canada en droit international demonstrates the pivotal role that Canada has played in the development of international law and signals the essential contributions the country is poised to make in the future.