Background: There is a paucity of literature qualitatively exploring adolescents’ experiences in secure care, which is an essential consideration for future service design. We aimed to increase understanding of factors which contribute both positively and negatively to these young people’s experience. Methods: A systematic review was conducted following PRISMA guidelines. Studies were identified by searching five online databases in June 2024. The quality and risk of bias of each study meeting inclusion criteria was independently assessed by two authors using the Crowe Critical Appraisal Tool. Results: 26 relevant studies were identified. Analysis revealed key themes: relationships/communication with others, rules and regulations, thoughts towards self and perspectives on treatment plans. Effective care appeared linked to supportive, empathetic staff and a balance between regulation and freedom. ’Peer solidarity,’ based on shared experiences, appeared important, fostering trust and friendship. Transition periods, especially to adult services, were identified as disruptive and anxiety-inducing. The importance of personalised care plans and supportive, therapeutic environments was emphasised, though findings varied across settings and age groups. Most papers were of moderate to high quality. Conclusions: Our findings offer valuable insights for professionals involved in design of supportive secure care environments tailored to the needs of involved young people. Future research should focus on directly exploring the lived experiences of less explored populations, such as the impact of neurodiversity or living in the developing world, on young people’s experience of secure care. This would ensure a more inclusive range of perspectives shape effective and compassionate care strategies.