Higher Education Institutions can play a crucial role in tackling today’s complex societal challenges through their innovation capacity. This capacity could be further unleashed by leveraging their vast knowledge base and opportunities for experimentation, collaboration, and co-creation on campus sites. In this regard, Living Labs represent a promising approach to solving complex social problems and are already being used in many Higher Education Institutions worldwide. However, there remains a need for a comprehensive understanding of their implications and implementation requirements, particularly when Higher Education Institutions aim to structurally harness their sustainable transformation potential beyond single initiatives. As such, there is a growing demand for concepts and tools that allow Higher Education Institutions to move from facilitating individual living lab initiatives to a more comprehensive approach. Responding to this demand, this chapter aims to support Higher Education Institutions in establishing the Campus as a Living Lab. Drawing on insights from an international Community of Practice, existing literature, and case studies, we offer a conceptualization of the “Campus as a Living Lab,” distinct from the traditional approach of individual living lab initiatives. The Campus as a Living Lab is a comprehensive, connected, and firmly embedded approach, striving to create synergies, knowledge exchange, and cross-fertilization. The whole campus and the organization are understood as a living lab, providing fertile ground for sustainable experimentation and innovation. We clarify the development stages of implementing this approach and introduce a practical tool for launching the Campus as a Living Lab, adaptable to diverse contexts. This chapter encourages Higher Education Institutions to transition from hosting stand-alone living labs and experiments to an integrated approach, enabling them to utilize their unique position to make significant contributions to sustainable transformation processes.