Despite overwhelming international evidence of elevated rates of poor mental health in LGBTQ+ youth compared to their cis-heterosexual peers, we know relatively little about effective mental health services for this population group. This study aims to produce the first early intervention model of “what works” to support LGBTQ+ youth with emerging mental health problems. Utilizing a mixed method case study, we collected data across 12 UK mental health service case study sites that involved: (a) interviews with young people, parents, and mental health practitioners (n = 93); (b) documentary analysis; (c) nonparticipant observation. The data analysis strategy was theoretical using the “explanation-building” analytical technique. Our analysis suggests an intersectional youth rights approach with 13 principles that must be enacted to provide good mental health services as advocated by the United Nations Convention on the Rights of the Child and World Health Organization. This approach should address the multiple forms of marginalization and stigmatization that LGBTQ+ youth may experience, enable informed independent decision-making, and uphold the right to freedom of safe self-expression. A rights-based approach to mental health services for LGBTQ+ young people is not prominent. This needs to change if we are to tackle this mental health inequality and improve the mental well-being of LGBTQ+ youth worldwide.