In this chapter we provide an overview of campus ecology and ecological systems theory as applied to the study of higher education, most often to research on college students. We describe Bronfenbrenner's developmental ecological model and its application of it to the study of college students. We then discuss affordances and limitations of this approach, including criticism of its lack of attention to systems of privilege and oppression in the higher education environment. We present a number of innovative approaches to using the Bronfenbrenner model that address these limitations, as well as adaptations to the model that incorporate critical theory, queer theory, and Indigenous Knowledge Systems.