The concept of a ‘just transition’ has become strongly linked to climate change and the idea that the process of decarbonising society needs to be done in a way that is fair to all. However, it is equally relevant to other areas in which a transition is needed. This article explores what a just transition might mean for the reform of Aotearoa New Zealand’s oceans management system. It argues that the concepts of justice and fairness are a useful way not only to manage the process of change, but also to frame and justify why change is needed. Different conceptions of justice – distributional equity, environmental justice, intergenerational equity, ecological justice and procedural justice – are all important lenses to look through when asking the hard questions about what the future of our seas should look like.