Due to increased levels of stigma, discrimination and victimization Lesbian, Gay, Bisexual, Transgender, Queer, Questioning or Intersex (LGBTQI+) youth face particular challenges in society. With the intention of better understanding the challenges and issues that LGBTQI+ youth are experiencing, this systematic review explored qualitative studies with a focus on mental health services and the requisite social support service policies and programs for LGBTQI+ youth. Qualitative research systematically examines the expressed thoughts and feelings of the research participants, and through reflective analysis of the themes and links discussed, can provide rich and nuanced understanding. A synthesis of the included studies identified five core themes: (1) Isolation, rejection, phobia, need for support; (2) Marginalization; (3) Depression, self-harm and suicidality; (4) Policy and environment; and (5) Connectedness. Key results suggest that community, school, and family resources to support resilience will optimize LGBTQI+ mental health. This systematic review of qualitative research provides a source of rich information to inform the provision of services and policies that will address the disparity into mental health statistics for the LGBTQI+ population.