This article tenders an inaugural discussion of how conceptual change theory can contribute to deeper understandings of what is conceptually involved when people attempt (or succeed) to transition from multi- and interdisciplinarity to transdisciplinarity. After explaining the nuances of Newtonian thinking (framed as formal rather than postformal thinking), the article shares a comparison of multi-, inter-, and transdisciplinarity along four dimensions. Special attention is given to Nicolescuian transdisciplinarity, an approach predicated on the new sciences of quantum physics, chaos theory, and living systems theory (rather than Newtonian and Cartesian thinking). Nicolescuian transdisciplinarity is a new methodology for creating knowledge and it comprises three axioms: multiple Levels of Reality and the Hidden Third; the Logic of the Inclusive Middle; and, knowledge as complex, emergent, and embodied. The discussion then turns to an overview of three basic approaches to conceptual change theory: knowledge as theory, knowledge as elements, and knowledge as context. The author then applies conceptual change theory to understand what is involved in moving toward transdisciplinary thinking, including four elements necessary for conceptual change to occur (intelligibility, plausibility, fruitfulness, and dissatisfaction with existing conceptualizations and mental models). The article concludes with the idea that transdisciplinary thinking is a form of postformal thinking (especially paradigmatic order thinking) and suggests that future conceptual shifts toward transdisciplinarity involve achieving a transdisciplinary conceptual tipping point.