This chapter explores the governance mechanisms necessary for transitioning to a circular economy in liveable cities, using the city of Vienna as a case study. The chapter presents the concept of the ‘butterfly potential’, drawing parallels between the transformation of a city and the metamorphosis of a caterpillar into a butterfly. It emphasises the importance of circular economy principles – reducing waste, reusing materials, and regenerating natural systems – as key components of creating a sustainable, resilient city. Vienna’s approach, highlighted through its Smart City Climate Strategy and the DoTank Circular City Vienna 2020–2030 programme, illustrates how a city can lead the way in circular innovation. The chapter discusses the governance strategies employed by Vienna, focusing on cross-sectoral collaboration, stakeholder engagement, and the integration of circular principles into urban development policies. Additionally, the chapter introduces the Quadruple Helix model, emphasising the need for academia, industry, government, and civil society to work together in fostering circular city systems. By showcasing the transformative potential of circular governance frameworks, the chapter argues that cities like Vienna can serve as models for achieving urban resilience and sustainability through innovative governance, policy coherence, and active public participation, ultimately enabling cities to thrive within planetary boundaries.