Background: Doping is a significant issue in sport. To date, research efforts to inform doping prevention have lacked any guiding framework for research priorities. To ensure future research endeavors are coordinated, sustainable and focused on end-user priorities, a research agenda, informed by practical needs and expert knowledge, is needed. For the first time, this study brought together an international group of practitioners and academic researchers to co-create a research agenda for doping prevention.Methods: The Delphi consensus method was used to identify the most important topics for social science research on doping prevention, as well as specific questions that need addressing. Based on eligibility criteria for key stakeholders in anti-doping, 82 academics, practitioners and representatives of anti-doping organizations were invited to participate in this agenda-setting project. Based upon two substantive reviews of the doping literature and 12 focus groups with elite athletes across five European countries, a questionnaire was developed by social science experts in anti-doping to assess the importance of 15 potential research topics and identify key research questions for each. In Round 1, an expert panel (n = 57) completed this questionnaire. In Round 2, expert panel members (n = 33; 42% attrition from Round 1) ranked the eight topic areas rated as most important in Round 1 on their relative importance, before doing the same for research questions within each topic area. Based on these rankings, a draft research agenda was created. In the final round, expert-panel members (n = 26; 54% attrition from Round 1) rated the degree to which they accepted this draft agenda and the feasibility of its delivery over the next ten years, as well as identifying possible barriers and facilitators to its implementation.Results: The results of Round 1 and Round 2 were used to create a research agenda consisting of 18 research questions stratified across eight topic areas. This draft agenda was either fully (n = 16) or mostly (n = 9) accepted by the expert panel in Round 3 (96.2%). These research topics focus on the effectiveness of anti-doping interventions/education programmes, athlete environment (developmental influences, role and knowledge of the athlete entourage), long-term development of protective and risk factors for doping in athletes and their entourage, athletes' experiences of key procedures and their perceived place in the anti-doping system. Conclusions: For the first time, a rigorous exercise was conducted to create a research agenda for doping prevention research. Adoption and application of this agenda should lead to better coordination, more efficient use of available funding resource, enhanced uptake of research findings by doping-prevention practitioners and in turn more effective anti-doping and clean-sport education.