Background Suicide bereavement during adolescence is associated with significant psychological, social, and educational impacts. While recent reviews have examined postvention following peer deaths within schools, little is known about support for students bereaved by family or community suicides, or about students’ experiences of such support, and the nature and extent of school-based support provided to affected students remains poorly characterised. Objectives This scoping review will map the available evidence on school-based postvention practices for secondary school students bereaved by suicide, addressing four research questions: what postvention practices are described in the literature;; what are students’ experiences of these practices and their support needs; what evidence exists regarding staff preparedness and training in delivering postvention support; what evidence exists for students bereaved by a suicide outside the school community? Methods This review will follow Joanna Briggs Institute (JBI) scoping review methodology and will be reported in accordance with PRISMA-ScR guidelines. A systematic search of five databases (PsycINFO, PubMed, ERIC, CINAHL, and ProQuest Dissertations and Theses Global) will be conducted alongside grey literature searching. Records will be screened against Population, Concept, and Context (PCC) eligibility criteria. Data will be extracted using a standardised form and synthesised narratively in relation to each research question. Discussion Findings will map the breadth of school-based postvention practices, identify gaps in the evidence base, and highlight priorities for future research and practice in supporting all suicide-bereaved students in secondary schools.