Innovation networks are embodied and shaped by their participants. This paper examines actors' roles in living labs, which are defined as networks of open innovation. The study utilizes four approaches to roles: structuralist, symbolic interactionist, resource-based, and action-based approaches. Our empirical analysis of 26 living labs in four different countries identifies a number of actor roles associated with open innovation. In addition, it reveals four role patterns characteristic of living labs: (i) ambidexterity, (ii) reciprocity, (iii) temporality, and (iv) multiplicity. These patterns distinguish actor collaboration in networks characterized by heterogeneous actors, the coexistence of individual and shared motives, high degree of openness, and user involvement. Scholars and practitioners of innovation learn that understanding of role patterns in living labs can contribute to building, utilization, and orchestration of open innovation networks.