Research has shown links between a number of safe school strategies and academic, social, and behavioral success among sexual minority students (students who may be lesbian, gay, bisexual, transgender, queer or questioning [LGBTQ]). The SOGI-3P study of population-based data from schools, school principals, and students will contribute to fuller understanding of the role of school policies, programs, and practices (“3P”) focused on comprehensive sexuality education (CSE) and sexual orientation and gender identity, and their association with school climate and student well-being and achievement. The study will address a number of limitations in the existing knowledge base; in doing so, the results will directly address strategy and planning questions: Which SOGI-focused policies or practices have the greatest impact on school climate and student well-being?