The movement incorporating sustainability into the academic mission of higher education has grown quickly in the last few decades. At the same time, vast interpretations of sustainability exist as institutions work to incorporate it into the curriculum. Therefore, using interviews with 42 individuals and observations of 67 courses, this study offers a theory of Education for Sustainability (EfS), which provides conceptual development for the path from learning to teaching in EfS. A framework for instructors (a macro-narrative of sustainability), a typology of EfS courses, and implications for practice are discussed.