Anxiety, depression, and suicide are leading causes of disability and death among young people, globally. Schools are an ideal setting to target young people's mental health, yet young people's beliefs about and experiences with school mental health and suicide prevention are not well understood. This gap in knowledge contradicts both national and international youth mental health recommendations and the United Nations Convention on the Rights of the Child, which collectively advocate for understanding young people's perspectives on matters concerning them, including school mental health. Therefore, the Mental Health of Youth Story (MYSTORY) study explored young people's perspectives on school mental health and suicide prevention using a participatory-based approach incorporating photovoice. MYSTORY consisted of a community/university partnership involving young people as participants (n = 14) and advisors (n = 6). Experiential, reflexive thematic analysis (TA) within a critical approach generated three themes relating to young people's experiences with and beliefs about school mental health promotion and suicide prevention. Findings highlight the critical role of schools in impacting young people's mental health, with the need to amplify youth voice and involvement in school mental health evident. Our study addresses an important gap by employing participatory-based approaches to explore young people's perspectives on school mental health and suicide prevention. This is the first known study to explore young people's perspectives on their voice and involvement in school mental health. Findings have important implications for youth and school mental health and suicide prevention research, policy, and practice.