This Companion sheds light on the law and practice of the International Maritime Organization (IMO), which plays a key role in securing safe, secure, and efficient shipping on clean oceans. Considering core elements of IMO history, this insightful Companion delineates how the Organization has revitalized its law-making powers, encompassing an increasing number and range of maritime-related activities. Taking into account the perspectives of flag, port, seafaring, and ship-owning states, the chapters focus on areas of increasing concern such as compliance and enforcement, and ocean governance. Expert contributors critically examine the efforts made and limitations encountered by the IMO in contributing towards achieving the United Nations Sustainable Development Goals, exploring the potential for building a sustainable and inclusive maritime governance. Ultimately, this Companion showcases how the IMO evolved from an ostensibly consultative inter-governmental forum into an active global standards-setting organization. Comprehensive in scope, The Elgar Companion to the Law and Practice of the International Maritime Organization is an essential resource for students and scholars of public and private international law, transport law, and governance studies. Policymakers, legislators and practitioners working in international maritime law will also benefit from the broad coverage of legislation and policy issues.