American schools are faced with complex and deep-rooted challenges such as poverty, discrimination, weak school-family relationships, low student motivation, and high student mobility. These challenges must be overcome if children and youth are to meet their needs for belonging, mastery, independence, and generosity; experience social competence and academic achievement in school; and ultimately enjoy a high quality of life. To support families, schools must utilize evidence-based approaches to teaching and learning. Moreover, these approaches must be embedded in efficient systems that allow practitioners to implement them with fidelity and cross the research-to-practice divide, which historically serves as a deterrent to school reform efforts. One promising approach to school reform that is gaining significant traction across the country is schoolwide positive behavior supports (SWPBS), a culturally responsive set of systems, practices, and data-based decision-making features designed to achieve socially important behavior change and improve academic achievement. One important feature of SWPBS is the evidence-based practice of engaging families as partners in schooling. Statewide initiatives, early childhood education programs, and K-12 schools engaged in SWPBS can establish and use home-school partnerships as leverage for school improvement. This article discusses how schools can foster family engagement in developing, implementing, and sustaining SWPBS; the challenges associated with such engagement; the barriers schools face; and the effective state- and school-level strategies that enhance family engagement and home-school partnerships. (Contains 8 resources.)