Over the last few decades ‘sustainability citizenship’ has been developing as a process of praxis – conscious, reflective practice – as concerned people have co-created novel ways to deal with critical environmental, social and economic challenges. These challenges demand that we live and work in ways that conform to Earth’s biophysical limits and principles of inter-and intra-generational equity. As such, sustainability citizenship is citizenship remade from the ground up with a thoroughly material basis and emerging set of ethics appropriate to our times. However, it remains a work-in-progress that will, ultimately, only be defined by our future activities.