In this article, the authors honor Catherine D. Ennis’s legacy by highlighting her unique and significant contributions to physical education research on curriculum and instruction. First, they discuss Ennis’s curricular philosophy and her empirical work along her career path. Then they review the major school-based curricular interventions she implemented, including the Movement Education; Sport for Peace; Science, PE and Me!; and The Science of Healthful Living curricula to demonstrate Ennis’s commitment to curricular development in physical education. In this process, they share with the reader Ennis’s contributions to curriculum development theories, curriculum intervention research, and physical education practices.