User engagement, stakeholder involvement, and public consultation in sustainability research have received increased attention over the last decade. Key driving factors behind this are that social outcomes, policy relevance, and user engagement have all become requirements for securing research funding. Many articles have provided compelling arguments for the need to reconsider why, when and how users are engaged within the research process. We propose a typology of user engagement strategies in research, focusing on the actual research process and emphasizing types of engagement in research. We illustrate these types with a comparative analysis of empirical examples from three interactive sustainability research projects, based in Canada and Switzerland. The article discusses the challenges that require a reconfiguration of institutional and organizational structures to seize the full potential of interactive sustainability research.