Background: With support from the Radcliffe Institute for Advanced Study at Harvard University, we convened researchers representing palliative care, psychosocial oncology, spiritual care, oncology, and psychedelic-assisted therapies. We aimed to define priorities and envision an agenda for future research on psychedelic-assisted therapies in patients with serious illness. Over two days in January 2020, participants engaged in an iterative series of reflective exercises that elicited their attitude and perspectives on scientific opportunities for this research. Objectives: The aim of the study is to identify themes that shape priorities and an agenda for research on psychedelic-assisted therapy for those affected by serious illness. Methods: We collected data through preconference interviews, audio recordings, flip charts, and sticky notes. We applied thematic qualitative analysis to elucidate key themes. Results: We identified seven key opportunities to advance the field of psychedelic-assisted therapies in serious illness care. Four opportunities were related to the science and design of psychedelic-assisted therapies: clarifying indications; developing and refining therapeutic protocols; investigating the impact of set and setting on therapeutic outcomes; and understanding the mechanisms of action. The other three pertained to institutional and societal drivers to support optimal and responsible research: education and certification for therapists; regulations and funding; and diversity and inclusion. Additionally, participants suggested epistemological limitations of the medical model to understand the potential value and therapeutic use of psychedelics. Conclusions: Medicine and society are witnessing a resurgence of interest in the effects and applications of psychedelic-assisted therapies in a wide range of settings. This article suggests key opportunities for research in psychedelic-assisted therapies for those affected by serious illness.