We investigated the characteristics of high-quality health and social care for people on probation and how they might be measured. Online open-ended survey responses and focus group data were analysed using thematic analysis. Providing high-quality care involves an understanding of the population's needs; tailoring practice to accommodate and meet individuals' needs; inter-agency collaboration; and seeking and acting on lived experience input. High-quality care is evidence-based and accessible and produces positive outcomes for people on probation. Foundations for achieving these outcomes are supportive, trusting and consistent supervisory relationships (working alliances) with professional practice that is sufficiently resourced, compassionate and person-centred.