Background and objective: Homelessness is a growing issue in the United Kingdom (UK). Counselling psychology in the United States of America (US) has made working for social justice a part of its professional identity and recognises that engaging with individuals experiencing homelessness is part of this work. There have been calls for the discipline in the UK to follow suit in making social justice work a part of its identity and recognising homelessness as an issue of social justice. Homelessness is largely absent from UK counselling psychology literature and it is important for training programmes to consider how they can support and prepare trainees to engage with individuals experiencing homelessness. The purpose was to explore the experiences of individuals who had engaged in psychological therapy while homeless to learn what they found helpful or unhelpful in the therapeutic process. As well as this, perspectives were sought from psychological therapists who had worked with individuals who were homeless to learn what aspects of their training were helpful or unhelpful in preparing them for this work. The aim was to identify ways that therapeutic training programmes can prepare trainees to engage with people who are homeless. Method: Data was collected from two participant groups. Individual interviews were completed with eight psychological therapists who were recruited from organisations throughout the UK, and a focus group focus group with the seven individuals who were homeless and recruited through a hostel. An inductive thematic analysis was carried out on the interview data to find out what would be helpful in therapeutic training, and on the focus group data to find out what was helpful in the therapeutic process. A template analysis was then carried out on both data sets to identify recommendations for how therapeutic training programmes could support trainees to engage with individuals who are homeless. Findings: The themes identified from the inductive analysis of the interviews were: Preparedness to work therapeutically with individuals experiencing homelessness, Awareness of homelessness as a context, The therapeutic process: Approaches & Challenges, and The therapeutic relationship (Therapist's perspective). The one theme identified from the inductive analysis of the focus group was: The therapeutic relationship (Client's perspective). The codes identified from a template analysis of both data sets were: Specific input on homelessness, Issues of social justice, and Wider Influence of Psychology. Conclusions: This research highlights differences in therapists' feelings that their therapeutic training was helpful in preparing them to work with individuals experiencing homeless, suggesting a further disparity in the extent to which trainees are being taught about homelessness and social justice across therapeutic training programmes in the UK. Individuals who received therapy while homeless consider power to be a key consideration in the maintenance of the therapeutic relationship. This research provides several recommendations about how therapeutic training programmes can support trainees to engage with individuals who are homeless through the provision of designated training, research, and practice opportunities. The wider implications of this research for other professions is also discussed.