Schools influence children’s developmental outcomes across multiple domains, including academic, social, emotional, behavioral, and physical. School district wellness policies are powerful mechanisms that set clear expectations for health-related practices in school buildings and the surrounding community. A current challenge is that many health-related school policies are narrow, siloed, and reactive instead of proactive. In this paper, we: (a) describe how written food, nutrition, and physical activity district and state policies were strengthened in the United States in response to specific concerns about childhood obesity; (b) present how schools have historically addressed policies concerning children’s social, emotional, and behavioral health; and (c) propose using the Whole School, Whole Community, Whole Child (WSCC) model to strengthen the coordination and integration of school wellness policies. We conclude by describing recently developed tools to assist school districts in implementing the WSCC model. The Wellness School Assessment Tool (WellSAT) WSCC is a quantitative measure that districts can use to code their current written policies for alignment with the WSCC model. The WSCC Policy and Practice Blueprints are action planning tools that lead school and district leaders through a series of activities to strengthen the implementation of coordinated and integrated policies and practices. By using the WSCC model and accompanying implementation tools, schools can support the development of the whole child.