In recent years, more and more mathematical methods and results from the field of category theory have been employed in the foundations of physics. These methods enable us to reconsider conceptual and structural issues in the foundations of quantum theory and possibly beyond, often providing surprising insights and new points of view. The workshop "Categories, Quanta, Concepts" (CQC) will bring together researchers from a variety of backgrounds, physicists, mathematicians, theoretical computer scientists and philosophers, all with a common interest in the foundations of physics. With talks in the morning and workgroups and in-depth sessions in the afternoon, the workshop will provide ample opportunity for interaction between the participants from this emerging community. The workshop also serves as an ideal platform for PhD students to get insight into the field and to discuss their own work.