Abstract
This study introduces a participatory research design for co-creating sustainability innovations in tourism destinations by integrating complexity and design science within a participatory action research framework. Applied with 29 stakeholders in Barcelona, the approach combined semi-structured interviews, participatory systems mapping, collaborative design thinking, and reflective evaluation. Stakeholders engaged with visual tools, playful methods, and time-bound design sprints, which were perceived as more inclusive and empowering than conventional policy roundtables. The sequential layering of methods fostered purpose and progress, enabling collaboration among actors who do not typically work together. The research design translated complex sustainability challenges into actionable innovations and built consensus around collective solutions. Findings show that the approach strengthens stakeholder understanding of policymaking, builds trust, empowers collaborative innovation, and supports knowledge transfer between participants and researchers.