Although dyad interviews have become more widely used in research, little has been published about a triad interview approach, in which two interviewers guide an engaged, three-way conversation with an interviewee. We describe our experience of developing online triad interviews within a participatory health research project that explored different stakeholders’ experiences of a young people’s cancer service in the UK. A defining characteristic of this research was the practical involvement of community members with different experiences of cancer, who worked as co-researchers in community–academic partnership. The decision to develop the triad interview method was emergent. It centred upon the connectedness of a clinical researcher, a companion co-researcher and a participant interviewee around a topic of shared experience. We first describe, and then reflexively appraise our development and enactment of this method, exploring how perspectives such as positionality and enhanced rapport impacted our exploratory interview conversations. We suggest that triad interviews are an underexplored qualitative research method, and we propose that, as an explicit practice, they could be highly beneficial in some person-centred research contexts.