Reflecting a change in funding strategies for European research projects, and a commitment to the idea of responsible research and innovation in radiological protection (RP), a collective of research institutes and universities have developed a prospective Strategic Research Agenda (SRA) for Social Sciences and Humanities (SSH) in radiological protection. This is the first time such a research agenda has been proposed. This paper identifies six research lines of interest and concern: (1) Effects of social, psychological and economic aspects on RP behaviour; (2) Holistic approaches to the governance of radiological risks; (3) Responsible research and innovation in RP; (4) Stakeholder engagement and participatory processes in RP research, development, policy and practice; (5) Risk communication; and (6) RP cultures. These topics were developed through broad stakeholder consultation, in conjunction with activities carried out in the framework of various projects and initiatives (EU H2020 CONCERT programme, the EU FP7 projects OPERRA, PREPARE and EAGLE, the 2015-2018 RICOMET series of conferences, and the 2014 and 2016 International Symposia on Ethics of Environmental Health); as well as through dialogues with members of the European radiation protection research communities. The six research lines open opportunities to integrate a range of key social and ethical considerations into RP, thereby expanding research opportunities and programmes and fostering collaborative approaches to research and innovation.