Sustainability at Catholic colleges and universities involves elements of physical plant operations, food services, curricular design, and a host of other concerns. The imperative for Catholic higher education to engage with issues of sustainability is both practical and ethical, and is well supported by Catholic Social Teaching. The article addresses the tools provided by a variety of organizations, focusing on The Natural Step, which is based on four simple system conditions that incorporate an ethic dimension as central to sustainability. A discussion of Catholic Social Teaching and sustainability, as well as case study material and evidence about the present condition of sustainability in Catholic education are included.