Suicide is a leading cause of death for school-aged preteens and adolescents and a growing risk for younger children. Schools are the ubiquitous institutional context serving this age group. These trends suggest a need for knowledge and guidance related to school postvention efforts, yet the available research is limited. Focusing on postvention, or the period after a peer suicide occurs, is critical to youth suicide prevention because this is a time of elevated suicide risk for youth. Targeted postvention interventions in schools can mitigate youth suicide risk and limit contagion within a school's student body. This article explores the scientific literature related to school-based suicide postvention, describing the strength and limits of research supporting common recommendations for suicide postvention in schools. It identifies widespread recommendations for school postvention that have only preliminary supportive evidence and notes several areas in need of additional research. With clearer postvention best practices to guide their suicide crisis preparedness plans and postvention procedures, schools can better support students, families, and the community as a whole in order to prevent further tragedies.