The objective of the Cluster of Excellence (COE) Circular Bioengineering is to revolutionize the production and the life-cycle of goods by disaggregation, reconstruction and synthesis of bio-based materials. The COE achieves this through a cross-disciplinary coordinated thrust directed by groundbreaking research in the molecular biosciences and biotechnology. The successful bioeconomy here conceived builds on sustainably produced resources and on environmentally benign processes to perform conversion reactions and material-modifying processes. It also links the principles of a minimum requirement of substance and energy to a zero-waste stream production. The COE’s unique approach at Circular Bioengineering interconnects pioneering research on technology-integrated biosystems such as enzymes and cells with the assessment of environmental, economic and societal impact of the corresponding bioprocesses to catalyze the transition to a sustainable bioeconomy. The paradigm change that is the COE’s mission will also be manifest in the training of next-generation scientists by accompanying educational programs as well as in comprehensive outreach activities to the relevant stakeholder groups and the general public. The COE Circular Bioengineering serves the scientific community through its specialized units and generates an essential nucleus for the bioeconomy to develop. The COE is strongly supported by our five partner universities and their commitment to advance the circular bioengineering. BOKU University as consortium leader is joined by the University of Graz, the Technical University of Graz, the University of Vienna, and the Technical University of Vienna.