This chapter interrogates what practising ‘sustainability’ looks like within universities, with a focus on Higher Education Institutions (HEIs) in the UK, and explores pathways, through policies and people, to achieve this. The goal of this chapter is to demonstrate the context and options for institutional transformation, and to support students, staff or community members to strengthen sustainability in their institutions. We will reflect on the business (or purpose) and busy-ness of universities, including teaching and learning, research, community engagement and practical operations. We will discuss institutional ‘sustainability’ policies, how policies translate to practice, and how to engage people in policy and practice. In section “Introduction”, we outline the role that universities can play in transforming society towards a vision of sustainability and more sustainable practices. In the section on “Concepts of a Sustainable University”, we explore meanings and representations of a ‘sustainable university’. In the section on “Policies, People and Practices for Change”, we map out the institutional landscape for transformation: the policies, practices and people that influence sustainability transformation. We discuss the theoretical framing for sustainability practice, including socio-technological transitions, systems thinking, behavioural change, social practice and community building, to link individual action, institutional policies and wider societal aspirations. The section on “Student Voice and Case Studies of Action” supports student-led change through voice, action and activism, providing practical tools that you can use to drive change within your university and beyond. Finally, in the Conclusions, we conclude with the potential for individuals to be change agents, and for institutions to change, and how we can promote sustainability transformation through sustainable universities.