A well designed regulatory regime has a number of structural (design) features that will facilitate the achievement of regulatory objectives. For tuna and highly migratory fisheries in areas beyond national jurisdiction, our main objectives are preventing overfishing and destructive fishing practices, whilst enhancing the nutritional, social and economic returns from the fishing activity in a way that is consistent with the UN Sustainable Development Goals. This paper explains and shows how a range of regulatory design features can be developed and used to facilitate investment and change in the regulation of global tuna fishing to help meet these objectives. These features include: developing combinations of public and private regulatory instruments, targeting regulatory interventions at point of maximum impact, empowering a wider range of regulatory actors, and acting consistently with institutional and governance limitations. These will be illustrated with brief case studies. Since tuna fishing is a complex and dynamic system, and any regulatory intervention will change this system, we must be sensitive to the impact of such interventions and be prepared to continually adapt them in light of new information and experiences. For example, the introduction of property rights may make future regulatory change more difficult to implement because holders of rights will resist regulation that diminishes the value of their holding.