The health benefits of physical activity are well documented, and the important role that schools and physical education (PE) can play in reducing sedentary behavior and contributing to population health has been identified. Although effective teaching is ultimately judged by student achievement, a major component of teacher and school effectiveness studies has been student engagement. Thus, in PE, it is important to assess the teaching and learning processes related to expected outcomes, including what students and teachers do and how lessons are delivered. Within a public health context, it is then important to assess how teachers provide students with ample health-enhancing physical activity to help them become physically fit and to learn generalizable movement and behavioral skills designed to promote physical activity and fitness outside of class time. In this article, we emphasize that the future of PE in our nation's schools will depend on the ability of schools to provide programs that are perceived to be of importance to the public; moreover, we believe that the future of PE rests on the effectiveness of PE teachers to operate within a public health context. In addition, we also provide a summary of teacher effectiveness research within a public health context and offer visions for the future assessment and evaluation of PE teacher effectiveness that move beyond the PE lesson to include components of the comprehensive school physical activity model.