In the field of polymeric materials, a fundamental transition is required from synthesis out of fossil-based feedstock and one-time use to continuous reuse of polymeric products. This course explains what is needed to reach a circular polymer economy and provides a foundation in the principles of polymer sustainability. The course covers the principles of green chemistry, biobased and biodegradable polymers, lifecycle analysis, current challenges of polymer waste collection and sorting, recyclability of polymers and various recycling methods. Moreover, it discusses new research developments in the field of circular polymer materials. This teaching activity contributes to the achievement of the Sustainable Development Goals of the UN 2030 Agenda.