This article critically explores "if" and "how" outdoor education (OE) is a discipline. This exploration stems from our experiences that OE is often undervalued, and from the belief that if OE is considered a discipline, then it would have greater acceptance, enhanced academic standing, importance, resourcing and prestige. Our analysis is rooted in a six-component discipline model which provides a framework for examining OE in relation to commonly understood attributes of stand-alone disciplines. In this article, we examine the final three components of the model. First, we explore the reference disciplines, such as education, psychology and sociology, which inform the OE field. Second, we examine the principles and practices of risk and reflection to chart how OE's principles and practices have evolved over time. Finally, we report on the structures that support the OE field, such as academic programmes, journals, textbooks and curriculum. We draw on a range of historical and contemporary evidence to provocate on if and how OE is a discipline. We conclude the article with a discussion of the implications of these analyses juxtaposed alongside a discipline model and the challenges and opportunities that lie ahead for OE in the context of being a discipline.