As a discipline, educational psychology is somewhat idiosyncratic in terms of content and methodologies. Such idiosyncrasies are likely rooted in the philosophical history of the discipline which involves both the empirical tradition of Thorndike and the contextualized pragmatics of James and Dewey. Despite this, there is little teaching about epistemological and ontological beliefs in most educational psychology doctoral programs. The purpose of this research was to (a) describe educational psychology doctoral students' epistemological and ontological beliefs and (b) determine the effectiveness of a four-part activity in supporting students' learning about epistemology and ontology. This study represents scholarship of teaching and learning. We analyzed 14 doctoral students' responses to a four-part activity to describe their epistemological and ontological beliefs. Second, we used a parallel convergent mixed method design to analyze quantitative and qualitative data describing students' learning from the activity. Students showed eclectic epistemological and ontological beliefs that were overall more epistemologically relativist than realist. For ontology, there was much more variability on the extent to which students believed truth exists and can be known in the discipline. All students, regardless of their epistemological and ontological beliefs, showed growth through the in-class activity. This is the first study to describe the epistemological and ontological beliefs of a sample of doctoral students in educational psychology. The results of this study and the pedagogical materials on which they are based can help the discipline itself and its students become more aware of its philosophical history and diversity.