Supporting children and young people's mental health is a central aim of the UK government policy, with those with learning difficulties a particularly vulnerable group. This systematic review of research uses published literature to explore how access and participation in therapy might be facilitated for young people with learning difficulties. Twelve studies published 2000-2019 were identified, which described the experiences of access to, and participation in therapy for people with learning difficulties, although notably most of these involved adults. Findings indicated eight themes: pre-therapy, careful contracting, therapy is hard, idiosyncratic needs, therapeutic relationship, group therapy, reviewing therapy and it changed my life. These were organized into three chronological stages: setting up of therapy; therapeutic processes; and therapeutic outcomes. A number of strategies that can promote access and participation are suggested for professionals working therapeutically with young people with learning difficulties, around contracting, clear communication, the therapeutic alliance and the ending of therapy.