Due to serious social-ecological problems caused by current consumption patterns, ensuring sustainable consumption and production has become one of United Nations’ Sustainable Development Goals. In this context, the establishment of a sufficiency-orientated circular economy is considered a decisive lever for a social-ecological restructuring of current market economies. The circular economy seeks to maintain the flow of resources and materials by keeping them in use for as long as possible, while sufficiency aims to reduce overall consumption within ecological and social limits. While research and practice on implementing a circular economy have focused much on technical innovations, policies, and individual sectors, the role of human behaviour has not been addressed adequately. However, it is crucial to gain a better understanding of consumer behaviour for achieving sustainable development in general and a sufficiency-orientated circular economy in particular. Therefore, anyone aiming to promote or implement effective sustainability and circular economy strategies should actively engage in the debate on sustainable consumption. As such, the topic addressed in this chapter is not only of academic interest but also highly relevant for practitioners and policymakers seeking to drive systemic change towards sustainability. The chapter focuses on the role of sustainable consumption in the sustainable development debate by, first of all, introducing core definitions and concepts of sustainable consumption such as the concept of weak and strong sustainable consumption. It continues by discussing the different types of sustainable consumption behaviour, e.g. environmentally friendly consumption or collaborative consumption. Given the prevailing attitude–behaviour gap, the chapter then presents several barriers to sustainable consumption, such as convenience-related ones. Finally, the chapter focuses on a specification of the previous discussion to the case of a sufficiency-orientated circular economy by exploring what sustainable consumption should look like in order to promote a transformation towards a sufficient and circular society. Thereby, it outlines relevant concepts and influencing factors related to circular consumption.