This article introduces the special issue ‘Transformational change through Public Policy’. After introducing the idea of transformational societal change, it asks how public policy scholarship can contribute to fostering it; the research questions we need to do so; what actors we need to study; who our audiences are; and how we need to expand our theories and methods. In our conclusion, we draw five lessons from the special issue articles. Transformational change (1) often results from many instances of policy changes over extended periods of time; (2) involves social movements that reconceptualise problems and possibilities; and (3) requires policy changes across sectors and levels of society, from local communities to national or global communities. As a field, Public Policy will (4) never offer detailed instructions to create transformational change in all circumstances, but (5) must involve scholars taking on different roles, from engaged scholarship to theory development that each provide unique contributions.